2020 Elections Post-Mortem

On November 3, 2020, the United States ended a weeks-long electoral process. At stake was the presidency, control of the United States Senate (“Senate”) and House of Representatives (“House”), 11 governor’s mansions, and thousands of state and local offices. That day, I published “cheat sheets” to guide election viewers through state-level presidential returns, 35 Senate elections and the gubernatorial elections.

[Ed. note: This post, my 200th, is the longest I have written to date. It is fitting that a blog which found its data-driven footing in the wake of the 2016 elections would have its 200th entry address the aftermath of the 2020 elections, beyond mere repetition of the number “20.”]

As I write this on midnight EST on November 17, 2020, precisely two weeks after the elections concluded, these are the top-line results:

  • Only one governor’s mansion changed partisan hands: Republican Greg Gianforte won back the statehouse in Montana for the first time in 16 years. As of January 2021, Republicans will hold 27 governor’s mansions, and Democrats will hold 23.
  • Democrats basically held serve in state legislative races. For more details, please see here.

On balance, the 2020 elections affirmed the status quo: a nation roughly evenly split between Democrats and Republicans, though it remains possible the former could control, however narrowly, the White House, Senate and House for the first time since 2010.

Presidential election

Biden-Harris are closing on 79.0 million votes (50.9%), shattering the previous record of 69.5 million votes won by Democrat Barack Obama and Biden in 2008. Trump-Pence have just under 73.3 million votes (47.3%), ranking them second in history. Biden has now appeared on three of the four presidential tickets to receive the most votes, with Obama-Biden earning 65.9 million votes in 2012, edging out Clinton-Kaine in 2016 by about 65,000 votes. Third party candidates are receiving more than 2.8 million votes (1.8%), significantly lower than the 8.3 million votes (6.0%) such candidates received in 2016. Approximately 155.1 million votes have already been counted, with an estimated 4.1 million votes—mostly in California and New York—left to be counted. This ~159.2 million vote projection, or about 2/3 of all Americans eligible to vote, also shatters the previous record of 137.1 million votes set in 2016.

Biden-Harris’ 3.6 percentage point (“point”) margin is a 1.5-point increase from 2016, and 0.3-point decrease from 2012, making it the third consecutive presidential election in which the Democratic ticket won the national popular vote by between two and four points; adding 22 million voters did not fundamentally alter the partisan electoral divide. Based on my Electoral College model, a Biden-Harris win of 3.6 points equates to 296 EV, nearly the 306 EV they received; for a Republican ticket, this equates to 327 EV.

How did Biden-Harris win the Electoral College?

Table 1: 2020 and 2016 Presidential Election Results by State, Ranked from Highest to Lowest Biden-Harris Margin

StateEVWinnerClinton-Kaine MarginBiden-Harris MarginDelta
Rhode Island4Biden15.520.85.2
New Jersey14Biden16.915.5-1.4
New York29Biden22.513.7-8.8
New Mexico5Biden8.210.82.6
Maine4Biden (3)
New Hampshire4Biden0.47.47.0
North Carolina15Trump-3.7-1.42.3
South Carolina9Trump-20.4-11.78.7
Nebraska5Trump (4)-17.8-19.2-1.4
South Dakota3Trump-29.8-26.23.6
North Dakota3Trump-35.7-33.42.4
West Virginia5Trump-41.7-39.02.7
Average  Trump+3.6Trump+0.8D+2.8

As Table 1 reveals, Biden-Harris won 25 states and the District of Columbia (“DC”) by an average of 17.4 points, while Trump-Pence won 25 states by an average of 19.8 points; medians are 14.6—reflecting the 86.8-point margin in DC—and 18.6, respectively. Biden-Harris won seven states and DC totaling 97 EV by 20 or more points, while Trump-Pence won 11 states totaling 65 EV by that margin.

Biden-Harris won 19 states, DC and the 2nd Congressional district in Nebraska by at least 6.0 points, for a total of 228 EV. Add Nevada (6) and Michigan (16), which the Democratic ticket won by ~2.5 points, below their national margin, and the total increases to 250 EV.

At around 10:30 am EST on Saturday, November 7, the major news networks declared Biden-Harris the projected winner in Pennsylvania—and its 20 EV put Biden-Harris over the total of 270 needed to win the presidency. It also makes Pennsylvania—the state in which I was born—the “tipping point” state, as it puts Biden-Harris over 270 EV when states are ranked from most to least Democratic. But the margin stands at just 1.0 points, or just 68,903 votes; Biden-Harris also won Wisconsin (0.6 points), Arizona and Georgia (0.3 points each) by similarly small margins. The Democratic ticket has a total winning margin of 104,025 votes in these four states.

In the 25 states, plus DC, won by the Democratic ticket, the average increase in margin from 2016 was 3.4 points, while in states won by the Republican ticket the average increase was 2.1 points; overall, the average margin shift was 2.8 points. In the five states which switched from Republican to Democratic, the average increase was 3.0 points, led by a 3.8-point increase in Arizona and a 5.4-point increase in Georgia. While Biden-Harris lost North Carolina by 1.4 points and Texas by 5.7 points, they improved the margin by 2.3 and 3.3 points, respectively.

However, while Biden-Harris improved on the 2016 margins by an average 3.7 points in these four southeastern/southwestern states—states I suggested were fertile ground for Democrats—they basically held serve in Iowa (D+1.2) and Ohio (no change), while falling further behind in Florida (D-2.2); I will not speculate what role undelivered ballots in Miami-Dade County played in the latter state. This should not be surprising, as these were perhaps the most disappointing states for Democrats during the otherwise “blue wave” 2018 midterm elections.

In 2016, Trump-Pence won 306 EV by winning six states Obama-Biden won in 2012: the aforementioned Florida, Iowa and Ohio, plus Michigan, Pennsylvania and Wisconsin. The latter were decided by a combined 77,736 votes; Clinton-Kaine also lost Georgia by 211,141 votes and Arizona by 91,234 votes. In 2020, as Table 2 shows, Biden-Harris won the former three states—more than enough to give them an Electoral College victory—by a combined 233,945 votes: a shift of 311,681 votes, or just 0.2% of all votes cast. But the Democratic ticket also increased their margin in Arizona by 101,691 votes and in Georgia by a remarkable 226,296 votes.

Table 2: Changes in Margin from 2016 to 2020 in Five Key States

State2016 Dem Margin2020 Dem MarginIncrease, 2016-20

Overall, across these five states, the margin swung toward the Democratic ticket by about 640,000 votes, which is still less than 1% of all votes cast. But we can get even more granular than that. Early in 2017, I observed that in the three states that swung the 2016 election to Trump-Pence, the Clinton-Kaine ticket did about as well in the Democratic core counties—the urban centers of Detroit, Milwaukee/Madison and Philadelphia/Pittsburgh—as Obama-Biden had in 2012. What changed was a massive increase in Republican turnout in the other, more rural counties of those states. I ultimately concluded this resulted from a split between white voters with a college degree (more Democratic suburban/urban) and without a college degree (more Republican rural).

Table 3: Changes in Margin from 2016 to 2020 in Pennsylvania Counties

County2016 D Margin2020 D MarginIncrease, 2016-20
Phila Suburbs   
Major Urban   
All Other Counties-816,051-826,874-10,283

Table 3 shows just how this split played out in 2020, using Pennsylvania as an example. Compared to 2016, the margins for the Democratic ticket increased only at 21,000 votes in the heavily urban Democratic counties of Allegheny (Pittsburgh) and Philadelphia. And the 61 counties outside these two counties, excepting the four-county ring around Philadelphia, also held serve for the Republican ticket; Erie and Northampton Counties switched, barely, from Trump-Pence to Biden-Harris. In fact, the two parties may have reach voted saturation in these two areas. But those four suburban Philadelphia counties, swung even further toward the Democratic ticket, from a margin of 188,353 votes to nearly 291,422 votes, for a total increase of 103,069 votes, nearly the entire swing from 2016 to 2020.

What about the polling?

With most of the vote counted, Biden-Harris lead Trump-Pence nationally by 3.6 points, which is 4.6 points lower than my final weighted-adjusted polling average (“WAPA”) of 8.2 points.

For my final post tracking national and state polling of the 2020 presidential election, I estimated the probability Biden-Harris would win a given state. In 24 states/DC totaling 279 EV, the probability was at least 94.7%; Biden-Harris won all of them. In 20 states totaling 126 EV, the probability was 1.3% or less; Trump-Pence won all them. The remaining seven states were:

  • Florida (80.1%), which Biden-Harris lost
  • Arizona (77.5%), which Biden-Harris won
  • North Carolina (69.0%), which Biden-Harris lost
  • Georgia (56.4%), which Biden-Harris won
  • Ohio (39.1%), Iowa (37.0%) and Texas (28.4%), each of which Trump-Pence won

Florida and North Carolina were the only “misses,” though it should be noted Trump-Pence still had a non-trivial 19.9% and 31.0% chance, respectively, to win those states. Further, my final back-of-the-envelope EV estimate was 348.5 for Biden-Harris—subtracting the 44 combined EV of Florida and North Carolina essentially gets you to 306. The latter value is also very close to the 297.5 EV I estimated Biden-Harris would receive if all polls overestimated Democratic strength by 3.0 points.

Along those lines, my 2020 election cheat sheets included a projected Democratic-minus-Republican margin (“JBWM”), which adjusts final WAPA for undecided votes, along with recent polling errors in selected states. Compared to the final FiveThirtyEight.com margins/polling averages (“538”), JBWM margins were about 1.2 points more Republican.

Even so, as Table 4 shows, the JBWM margins were, on average, 3.4 points more Democratic than the final margins, and the 538 margins were 4.6 points more Democratic. When the direction of the difference is ignored, meanwhile, the differences between the two method vanish: an average absolute difference of 4.5 from JBWM margins compared to 4.8 for 538.

However, this overall difference masks a stark partisan difference: the mean JBWM difference was only 1.1 points more Democratic in states/DC won by Biden-Harris, while it was 5.9 points more Democratic in states won by Trump-Pence. The correlation between the Biden-Harris margin and the JBWM difference is 0.73, meaning the more Republican the state, the better Trump-Pence did relative to the final polling. In short, pollsters continue to undercount “Trump Republicans” in the most Republican states.

Table 4: 2020 Presidential Election Results by State, Ranked by Difference from JBWM Democratic-Republican Margin “Projection”

StateEVWinnerJBWM ProjectionBiden-Harris MarginDelta
West Virginia5Trump-20.4-39.0-18.6
New York29Biden28.313.7-14.6
South Dakota3Trump-15.6-26.2-10.6
North Dakota3Trump-23.2-33.3-10.1
New Jersey14Biden19.515.5-4.0
Maine4Biden (3)12.58.7-3.8
South Carolina9Trump-8.9-11.7-2.8
New Hampshire4Biden8.97.4-1.5
Nebraska5Biden (4)-17.8-19.2-1.4
New Mexico5Biden12.010.8-1.2
North Carolina15Trump-1.1-1.4-0.3
Rhode Island4Biden19.020.71.7
Average  Biden+2.6Trump+0.8D-3.4

To again get more granular, Table 5 lists the pollsters who assessed the national popular vote at least five times since January 1, 2019, sorted by distance from the actual national margin of 3.6%. Margins are weighted for time, but not adjusted for partisan “bias.”

Table 5: Top 2020 Presidential Election Pollsters, Final WAPA National Margin

Pollster538 RatingFinal MarginDelta
NORC (AllAdults only)C+11.3-7.7
USC DornsifeB/C10.4-6.8
Quinnipiac UniversityB+10.4-6.8
NBC News/Wall Street JournalA-10.1-6.5
Global Strategy Group/GBAO (Navigator Res)C+9.9-6.3
Data for ProgressB-9.8-6.2
Redfield & Wilton StrategiesC+9.6-6.0
ABC News/Washington PostA+9.2-5.6
Marist CollegeA+9.1-5.5
Echelon InsightsC+8.8-5.2
Change ResearchC-8.3-4.7
Fox NewsA-8.3-4.7
Research Co.B-7.8-4.2
Morning ConsultB/C7.6-4.0
Monmouth UniversityA+7.4-3.8
Firehouse Strategies/OptimusB/C7.4-3.8
RMG ResearchB/C7.1-3.5
Harris XC6.5-2.9
Suffolk UniversityA6.2-2.6
Emerson CollegeA-3.8-0.2
Rasmussen Reports/Pulse Opinion ResearchC+3.20.4

           * John Zogby Strategies/EMI Solutions, Zogby Analytics, Zogby Interactive/JV Analytics

These 32 pollsters accounted for 556 (80.6%) of the 690 polls conducted. On average, they estimated Biden-Harris would win the national popular vote by 8.2 points, identical to my final WAPA; the average miss was 4.5 points in favor of Biden-Harris. There was only minimal difference by pollster quality: the 11 pollsters with a rating of B or better missed by an average of 4.2 points, while the 21 pollsters with a rating of B- or lower missed by an average of 4.7 points. That said, three of the four pollsters who came closest to the final national margin—Zogby, Rasmussen and Civiqs—had ratings of B/C or C+; the fourth was Emerson College, rated A-. At the other end of the spectrum are seven pollsters who anticipated a double-digit national popular vote win for Biden-Harris: low-rated Opinium, NORC (who polled adults, not registered/likely voters), CNN/SSRS, Qriously and USC Dornsife; and high-rated Quinnipiac University and NBC News/Wall Street Journal.

Overall, though, the polling captured the broad contours of the 2020 presidential election—if not the precise margins—fairly well, with JBWM and actual Democratic margins correlated a near-perfect 0.99; the order of states from most to least Democratic was accurately predicted. It forecast a solid, if not spectacular win by Biden-Harris in the national popular vote, a restoration of the upper Midwestern “blue wall,” and continued Democratic gains in southeastern/southwestern states such as Arizona, Georgia, North Carolina and Texas, even as Florida, Iowa and Ohio become more Republican.

One final note: it is exceedingly difficult to beat an elected incumbent president. Since 1952, it had happened only twice (1980, 1992) in eight chances prior to 2020[1]; Biden-Harris beat those 1:3 odds convincingly.

Senate elections

Democrats entered 2020 needing to flip a net four seats—or three seats plus the White House—to regain the majority for the first time since 2014. As Vice-President-elect, Kamala Harris breaks a 50-50 tie.

Table 6: 2020 Senate Election Results by State, Ranked from Highest to Lowest Democratic Margin, Compared to Pre-Election “Fundamentals”

StateWinnerFundamentalsFinal Dem MarginDelta
Rhode IslandReed24.433.08.6
New JerseyBooker18.415.8-2.6
New HampshireShaheen6.515.79.2
New MexicoLujan8.56.1-2.4
Georgia Special???-8.0-1.07.0
North CarolinaTillis-6.4-1.74.7
South CarolinaGraham-16.1-10.35.8
South DakotaRounds-26.2-31.5-5.3
West VirginiaCapito-35.9-43.3-7.4
AverageD+1 to 3GOP+8.9GOP+7.0D+1.9

Table 1 summarizes these elections; for the Georgia special election and Louisiana, margins are for all Democrats and all Republicans. Democrats John Hickenlooper and Mark Kelly defeated Republican incumbents in Colorado (Cory Gardner) and Arizona (Martha McSally), respectively, while Republican Tommy Tuberville defeated Democratic incumbent Doug Jones in Alabama. This leaves Democrats two seats shy of 50-50, pending the January 5 runoff elections in Georgia. Incumbent Republican David Perdue edged Ossoff on November 3 by 1.7 points, but fell 0.3 points short of the 50.0% needed to win outright. In the special election necessitated by the retirement of Republican Johnny Isaakson in December 2019, Warnock (32.9%) led incumbent Republican Kelly Loeffler (25.9%) by 7.0 points in the all-candidate “jungle primary;” overall, Republican candidates earned 49.4% of the vote and Democratic candidates earned 48.4%, with 2.2% split between a handful of third-party candidates.

When I took a “wicked early” look at these elections, I assessed the Democrat’s chance in each election using their “fundamentals,” or the sum of the state’s partisan lean (calculated using my 3W-RDM), the Democratic margin on the generic ballot and incumbency advantage.[2] For Table 6, the generic ballot is the difference in the percentages of the total vote for all Democratic House candidates and for all Republican House candidates; Democrats are ahead by 2.0 points.

On average, Democrats overperformed “expected” margins by 1.9 points. In the 13 elections won by Democrats, the overperformance was 2.5 points, while in the 20 elections won by Republicans, the overperformance was just 0.9 points; Democrats overperformed in the two Georgia Senate races by 7.0 and 8.3 points, confirming how rapidly it is moving toward swing-state status. The biggest Democratic overperformance—fully 10.7 points—was in Arizona, which in 2021 will have two Democratic Senators (both of whom beat McSally) for the first time since 1953. Other Senate elections in which the Democratic candidate overperformed by at least 9.0 points were New Hampshire, and three states where Democrats fell short in their attempt to win back a Republican-held seat: Montana, Kansas and Kentucky.

On the flip side, setting aside a 15.1-point underperfomance in Nebraska, the biggest Republican overperformance was in Maine, where incumbent Susan Collins, first elected in 1996, “should” have lost by 5.5 points. Instead, she won by 8.9 points; this is a 28-point decline from 2014, when Collins won by 37 points. Pending the results of the Georgia runoff elections, Maine is the only state in 2020 to have a Democratic presidential victory and a Republican Senate victory, with a gap of 17.6 points. It will be interesting to see whether Collins adjusts her voting in the next Senate. Other large Democratic underperformances, finally, took place in Michigan, where first-term Democratic Senator Gary Peters beat Republican John James by only 1.5 points and in West Virginia, which grows more Republican every year.

On the whole, though, expected and actual margins aligned nearly perfectly, with a 0.94 correlation.

What about the polling?

As with the presidential election, the final polling averages/projected margins were far less accurate, as Table 7 shows; I did not calculate a projected final margin for the Louisiana Senate election.

Table 7: 2020 Senate Election Results by State, Ranked by Difference from JBWM Democratic-Republican Margin “Projection”

StateWinnerJBWM ProjectionDemocratic MarginDelta
West VirginiaCapito-20.6-43.3-22.7
South DakotaRounds-19.9-31.5-11.6
New JerseyBooker24.615.8-8.8
South CarolinaGraham-4.7-10.3-5.6
New MexicoLujan10.06.1-3.9
North CarolinaTillis1.1-1.7-2.8
New HampshireShaheen14.415.71.3
Georgia Special???-3.9-1.02.9
Rhode IslandReed29.633.03.4
AverageDem+1 to 3GOP+0.6GOP+6.4D-5.8

The polling may have been within historic parameters for the presidential election, but it was far worse in the Senate elections, with the JBWM margins overestimating Democratic margins by an average of 5.8 points, almost exactly the 6.0 points by which 538 margins erred on average; ignoring direction, the average misses are 6.3 and 7.0 points, respectively. That said, the correlation between the actual and projected Democratic margins was 0.97, meaning the polling correctly forecast the order of Senate elections from most to least Democratic.

These overall averages again mask substantial partisan differences. In the 13 states where the Democratic nominee won, the average miss was a historically-reasonable -2.9 points, but in the 19 states (excluding Louisiana) where the Republican nominee won, the average miss was an astounding -8.3 points. Put another way, in the 15 states Trump-Pence won by at least 10 points which also held a Senate election, the average Senate miss was -8.9 points, while it was -3.3 points in all other states. Somewhat reassuringly, in the five states whose presidential margin was within five points also holding a Senate election (Arizona, Georgia, Michigan, North Carolina), the miss was only -2.2 points. Overall, the correlation between the Biden-Harris margin and the JBWM margin error was 0.57, confirming the idea pollsters systematically undercounted Republican support in the most Republican states.

My back-of-the-envelope estimate was a net gain of five Democratic seats in the Senate, with at least a 77% chance Democrats would regain control; these values dropped to 30% and either two or three seats with the assumption all polls systematically overestimated Democratic strength by three points. Democrats will ultimately net between one and three seats, corresponding more with the latter assumption. I estimate the probability Democrats win both Georgia Senate runoff elections—and thus the Senate—is between 25 and 50%, depending on the degree of ticket-splitting.

From a purely mathematical perspective, the largest Democratic underperformances occurred in the Senate elections in West Virginia, Wyoming, South Dakota and Nebraska: four extremely Republican states. But from a strategic perspective, the most disappointing elections were in Maine (-12.2) and North Carolina (-2.8), where incumbent Republican Thom Tillis narrowly held off a challenge from Democrat Cal Cunningham, who may have been hurt by a sexting scandal; given the narrowness of his victory (1.7 points) and the increasingly swing status of North Carolina, Tillis’ voting patterns also merit watching. These were the two states besides Arizona (98.1%) and Colorado (99.5%) in which I estimated the Democratic nominee had at least an 85% chance to defeat a Republican incumbent; I also thought Democrat Theresa Greenfield was roughly even money to defeat incumbent Republican Joni Ernst, despite projecting a final margin of 3.6 points for Ernst; the latter won by 6.6 points.

There were four additional Senate elections—in Alaska, Kansas (open seat), Montana and South Carolina—where I estimated the probability of a Democratic flip was between 11.7 and 26.4%. In a sign of how good these elections were for Republicans, their nominees won all four elections by an average of 11.3 points, a mean 7.5 points more Republican than projected. In fairness, these states tilted an average 19.2 points more Republican than the nation as a whole coming into the 2020 elections. A similar story can be told in Texas, which tilted 15.3 points more Republican, but where Democrat M.J. Hegar “only” lost by 9.8 points to incumbent Republican John Cornyn, beating expectations by 0.6 points.

Put simply, assuming a loss in Alabama, Democratic hopes of winning back control of the Senate relied on flipping two Senate seats in Democratic states, then winning at least two more seats in states ranging from somewhat Republican—Iowa, North Carolina, Arizona, Georgia—to extremely Republican—Alaska, Kansas, Montana, South Carolina and Texas—all while Trump sought reelection. To date, Democrats have only flipped seats in Colorado (D+2.2) and Arizona (D-9.7) while winning back the Vice-Presidency, losing tough elections in Iowa, Maine and North Carolina, while never really being in contention anywhere else. Senate control now rests on Democrats winning two Senate runoff elections in a nominally Republican state (D-9.6), but one where Biden-Harris won, improving on Clinton-Kaine’s by 5.4 points.

Gubernatorial elections

Unlike those for the White House and Senate, there was very little drama in these elections. Two Democratic incumbents—John Carney of Delaware and Jay Inslee of Washington—were expected to win easily; they won by margins of 20.9 and 13.6 points, respectively. Six Republican incumbents—Eric Holcomb of Indiana, Mike Parson of Missouri, Chris Sununu of New Hampshire, Doug Burgum of North Dakota, Phil Scott of Vermont and Jim Justice of West Virginia—as well as Republican Spencer Cox of Utah were expected to win easily, though I projected Parson to win by “only” 8.0 points (he won by 16.6 points). They won their elections by an average margin of 31.6 points!

The only possible drama was in Montana, where Republican Gianforte and Democrat Mike Cooney vied to win the governor’s mansion being vacated by Democrat Bullock, and North Carolina, where Democratic Governor Roy Cooper—who won extremely narrowly in 2016—faced Republican Dan Forest. Gianforte defeated Cooney by 12.4 points, easily exceeding a projected 4.5 points, while Cooper won by 4.5 points, not the projected 10.4 points. Still, my global projection was correct: a net gain of one governor’s mansion by the Republicans, giving them a 27-23 majority; this an overall net gain of seven governor’s mansions by the Democrats since 2016.

In these elections, Republicans strongly overperformed fundamentals (7.1 points) and JBWM projections (7.6 points). However, expected values were strongly skewed by Scott’s 41.1-point victory in extremely-Democratic Vermont (D+27.7) and Sununu’s 31.8-point victory in swing New Hampshire (D+0.1); exclude those two margins and DEMOCRATS overperformed expectations by 1.0 points—with Democrat Ben Salango exceeding what were admittedly very low expectations by 8.5 points. Meanwhile, in the four states with governor’s races won by Biden-Harris, Democratic gubernatorial nominees finished an average 8.9 points lower than projected, while in the seven states won by Trump-Pence, they finished an average 6.8 points worse than expected. Once again, the extreme disparity in presidential/Senate and gubernatorial voting in New Hampshire and Vermont—two of three states in solidly-Democratic New England, along with Massachusetts (Charlie Baker), to have very popular Republican governors. In fact, gubernatorial elections are among the only ones in which ticket-splitting is still relatively common: Biden-Harris won six states with a Republican governor,[3] while Trump-Pence won five states with a Democratic governor.[4]

House elections

A wide range of forecasters expected Democrats to net between five and 10 House seats[5]. I was highly dubious of this, to be honest, given the likelihood the margin for Democrats in the total national House vote would decline from the 8.6-point margin they earned in 2018; it would also be higher than the 1.1 points by which they lost in 2016, when they still managed to net six seats. However, because I was not closely tracking House races, I said nothing about my doubts.

According to the Cook House vote tracker, Democrats had earned more than 75.1 million House votes (50.1%), Republicans had earned just under 72.1 million votes (48.0%), with the nearly 2.2 million votes (1.8%) going to third-party candidates. A total of 150.0 million votes have been counted, 5.1 million less than those cast in the presidential election. The 2.0-point margin by which Democrats are winning the House vote—just under 3.1 million votes—is also lower than the 3.6 points, and 5.6 million votes by which Biden-Harris currently lead Trump-Pence. It is also much lower than the 9.7-million Democratic vote margin in 2018, albeit with 36.3 million more votes cast in 2020, reinforcing the conclusion a few million Republican-leaning voters “balanced” a vote for Biden-Harris with Republican votes elsewhere…or simply chose not to vote in down-ballot elections.

In the races that have already called, Republicans have gained 11 seats held by Democrats (two each in California and Florida, one each in Iowa, Minnesota, New Mexico, New York, Oklahoma, South Carolina and Utah), while Democrats have gained three seats held by Republicans (two in North Carolina, one in Georgia). This gives Democrats 221 seats, three more than needed for the majority, and Republicans 208 seats. Of the six seats yet to be called, Democrats currently hold four, with freshman Democrat Tom Malinowski leading by ~5,000 votes in New Jersey’s 7th Congressional District (“CD”). Giving that seat to the Democrats—and giving Republicans their open seat in New York’s 2nd CD—increases the totals to 222 Democrats and 209 Republicans.

That leaves four seats truly in doubt:

  • California’s 21st CD, where incumbent Democrat T.J. Cox trails Republican David Valadao, in a 2018 rematch, by 2,065 votes.
  • California’s 25th CD, where Democrat Christy Smith is within 104 votes of unseating Republican Mike Garcia, who won a special election in May 2020 after first-term Democrat Katie Hill resigned.
  • Iowa’s 2nd CD, where Democrat Dave Loebsack did not seek reelection; Republican Mariannette Miller-Meeks leads Democrat Rita Hart by only 47 votes!
  • New York’s 22nd CD, where Republican Claudia Tenney’s lead over incumbent Democrat Anthony Brindisi continues to shrink as New York votes are slowly counted.

Democrats will thus lose a net 8-12 seats compared to the 234-201 margin they had after the 2018 elections. This is a bad result for the Democrats, right?

Well, no…it suggests that polling-based expectations were flawed, because the fundamentals always pointed toward a net loss of House seats for the Democrats. Moreover, the comparison should be to 2016, because that is the last election in which Trump appeared on the ballot.

Following the 2016 elections, Republicans had a 241-194 House majority. Democrats were convinced, wrongly I thought, that gerrymandering by Republican legislators and governors would keep them in the minority for the foreseeable future. Looking ahead to the 2018 midterm elections, knowing Democrats needed to net 24 seats to regain the majority, I looked at all House elections from 1968 to 2016, and I noticed that what “predicted” net change in seats from one election to the next was not the national margin in a given election, but the change in that margin from the previous election. Figure 1 helps to illustrate this.

Figure 1:

In 2018, Democrats net a surprisingly-high 41 House seats, 17 more than they needed, most by narrow margins. It is then reasonable to expect that even a small decline in the Democratic share of the total national House vote would allow Republicans to “claw back” some of these seats Democrats currently lead the total national House vote by 2.0 points, fully 6.6-point decrease f 2018. Entering this value into the OLS regression shown in Figure 1 yields an estimated Democratic loss of 22.4 seats.

In other words, while Democrats expected to gain seats—based on what we now know was polling that underestimated Republican margins by 3-7 points—they should actually have been bracing themselves for a possible loss of the House itself. Instead, they “only” lost between eight and 12 seats, meaning they did far better than history would have suggested. Moreover, Democrats have net between 29 and 33 seats since 2016, earning control of the House in back-to-back elections for the first time since 2006-2008, something that seemed nearly impossible early in 2017.


Both Democrats and Republicans can find 2020 election results to celebrate.

Democrats won back the White House after just four years (beating 1:3 odds to defeat an incumbent), rebuilding their upper-Midwestern blue wall while expanding into the southeast and southwest; no Democratic presidential nominee has won both Arizona and Georgia since 1948. They also maintained control of the House of Representatives and made gains in the Senate; with two more wins in Georgia in January 2021, they regain control of the Senate as well. Democrats have not controlled both the White House and House since 2010.

Republicans, even as they lost the White House, gained as many as 12 seats in the House and staved off losing control of the Senate until January 2021 at the earliest. They net one governor’s mansion, giving them a 27-23 majority, and held their own in state legislative elections. Once again, Trump’s name on the ballot encouraged many more exurban and rural voters to vote than expected, ironically helping all Republicans but himself and his running mate.

Fans of bipartisan “balance” can also celebrate 11 states seeing different parties win their state’s electoral votes and serving as governor. Moreover, a record-smashing 155.1 million—and counting—Americans cast a ballot for president, which equates to two in three of all adults eligible to vote.

Finally, the polls erred substantially in favor of Republicans, with a miss of around 3.5 points compared to my final projections and 4.7 points relative to those from 538. Republicans fared even better in Senate and gubernatorial elections, beating final projections by around six points in the former and nearly eight points in the latter. These values mask a partisan split, with polls far more accurate for Democratic candidates than Republican ones. In the end, though, polls were far less accurate—in this Trump-led cycle at least—than simply considering a state’s recent partisan lean, the national partisan environment and incumbency. These fundamentals remain extremely predictive, at least relatively.

Until next time…please stay safe and healthy…

[1] 1956, 1972, 1980, 1984, 1992, 1996, 2004, 2012

[2] Democratic full-term incumbents=4.4, Democratic partial-term incumbents=2.2, non-incumbent=0, Republican partial-term incumbents=–0.4, -0.6, -1.6; Republican full-term incumbents=-2.4

[3] Arizona, Georgia, Maryland, Massachusetts, New Hampshire, Vermont

[4] Kansas, Kentucky, Louisiana, Montana, North Carolina

[5] The Cook Political Report hedged a bit, labeling 229 seats at least Lean Democrat, 179 seats at least Lean Republican, and 27 seats Toss-up. Of the Toss-ups, nine are held by Democrats, 17 by Republicans, and one by Justin Amash of Michigan, who switched from Republican to Independent in July 2019.

Your 2020 Election Cheat Sheets

Election Day 2020 has finally arrived. More accurately, the end of election season comes today, as over 100 million Americans have already voted. To help guide you through the coming hours of media coverage, I have attached two PDFs.

The first one allows you to track the results of the presidential election. For my last update and to understand how I aggregate all polls assessing Democratic presidential nominee Joseph R. Biden, Jr. versus Republican President Donald J. Trump, please see here.

The second one allows you to track, the results of the 36 Senatorial and 11 gubernatorial elections. In the column headed “538CL,” I list the final projected FiveThirtyEight.com Senate election margins using their “Classic” methodology. The analysts at 538 did not track gubernatorial elections this year. For my last update, see here.

Names of incumbents are underlined in italics, while, in open seats, the candidate of the incumbent’s party is in italics. Values highlighted in blue are projected Democratic gains, and values highlighted in red are projected Republican gains.

In both trackers, the column headed “JBWM” list my my best estimate of the final margins in each election, not the polling averages. In most states, this is essentially the same as the final polling average. Since my last update, I made two algorithm changes. First, I weight all poll conducted entirely after the final presidential debate on October 22 six times higher. Second, I halve the weight of any poll with a one-day field date.

However, in the 13 key Electoral College states of Arizona, Florida, Georgia, Iowa, Michigan, Minnesota, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Texas and Wisconsin, and in the key Senate battlegrounds of Alaska, Arizona, Colorado, Georgia, Iowa, Kansas, Maine, Michigan, Minnesota, Mississippi, Montana, North Carolina and Texas, I began by assigning between 0.5 and 3.0 percent of the total vote to third party candidates, essentially eyeballing their polling percentages and cutting them in half. I then adjusted the final polling margin, for states for which I had this information, by the average 2016-2018 miss, as calculated by Dave Wasserman. Finally, I divided the remaining–usually minimal–undecided vote based on the relative Democratic or Republican lean of the state and the early vote count as a share of the 2016 vote totals. Put simply, in strong Democratic states with high turnout, I gave two-thirds of the undecideds to Biden, in strong Republican states with lower turnout I gave two-thirds of the undecideds to Trump, and where the two metrics diverged, I split them evenly.

With that in mind, here are some general observations.

  1. Maine and Nebraska assign two Electoral Votes (“EV”) to the statewide winner and one each to the winner of the state’s two and three Congressional districts (“CD”), respectively. I did not analyze polling data from the 2nd CD of Nebraska or the 2nd CD of Maine. While I expect Biden to win the former (and the 1st CD of Maine), I have no clear sense of who will win the latter; Trump will easily win the other two CD in Nebraska.
  2. My final “product of EV probabilities” sums are 348.5 using all polls conducted since January 1, 2019, and 350.6 using only polls conducted since the national party conventions concluded on August 28. With a systemic three-point polling error favoring Republicans, the EV total drops to 297.5, and with a systemic pro-Democratic error the EV total jumps to 391.2
  3. In my 2020 presidential election cheat sheet, Biden wins a total of 290 EV in states where I project him to win by at least 2.2 points, including NE-2; the latter state is Pennsylvania, with 20 EV–losing it drops Biden to exatly the 270 he needs to win. Note that I “award” North Carolina to Trump, while 538 has Biden slightly favored there. I am far less certain of three states whose 83 total EV–Florida, Georgia and Texas–I “award” to Biden by very narrow margins; 538 has Trump slightly favored in Texas. Honestly, Biden could win all four of these states, Trump could win all four, or any combination in between. Thus, by my calculations, Biden could win anywhere from 290 to 373 EV–very close to my six-point polling error spread.
  4. Recall that there are two Senate elections in Georgia, one scheduled between Democrat Jon Ossoff and Republican incumbent David Perdue, and one being defended by incumbent Republican Kelly Loeffler in which all candidates run in the same election. In the former, I “award” the win to Ossoff, but if neither candidate reaches 50%–and Libertarian Shane Hazel routinely earns ~3% in public polling–there will be a runoff election on January 5, 2021. In the latter race, it is a near certainty Democrat Raphael Warnock will advance to a runoff election on January 5, probably–but not certainly–against Loeffler. As of now, Warnock is the strong favorite to win that election.
  5. Louisiana also has a “jungle” primary for Senate, with a runoff between incumbent Republican Bill Cassidy (if he does not reach 50% today) and Democrat Adrian Perkins a near-certainty.
  6. I line up exactly with 538 on Senate races, though the Senate race in Iowa is quite close. We both anticipate the next Senate to have 50 Democrats, plus two Independents who caucus with them, and 48 Republicans.
  7. However–keep an eye on Montana. Democratic Governor Steve Bullock is a very slight underdog against incumbent Republican Steve Daines, but could also easily eke out a narrow win. And the only remotely competitive governor’s race–an open seat battle between Democratic Lieutenant Governor Mike Cooney versus House Member Republican Greg Gianforte–is being held there as well.

And that is it.

Time to prepare a batch of blue lagoons, ready my bowl of blue and white M&M’s and settle in for a long night…or week.

Until next time…please stay safe, and if you have not done so already, please VOTE!

Quinnipiac University and Emerson College: Mirror-image pollsters?

In three earlier posts—most recently here—I analyzed all polls conducted by Emerson College (“Emerson”) of 2020 presidential, senatorial and gubernatorial elections. I found that they had a clear bias towards the Republican candidate, on average, compared to all other polls of the same election.

As I continue to analyze polls of the presidential election between former Vice President Joseph R. Biden, Jr. and President Donald J. Trump, as well as this year’s 35 Senate and 11 gubernatorial elections, I have observed the opposite mathematical bias for Quinnipiac University (“Quinnipiac”) polls.

In fact, as we will see, the two polling organizations nearly mirror each other in their mathematical bias.


Let us begin with the national race between Democrat Biden and Republican Trump. Using all 632 publicly-available polls released since January 1, 2019, I calculated a weighted-adjusted polling average (WAPA) of 8.3. That is, adjusting for time (with polls conducted after August 29 weighted and additional 1.5 times higher and polls conducted since September 29 3.0 times higher), pollster quality and partisan lean, Biden leads Trump by a little over eight points nationally. Emerson has an A- rating, and a historic lean of 0.3 points Democratic, while Quinnipiac has a B+ rating, and a historic lean of 0.2 points Democratic.

Table 1: State-level 2020 presidential election polling averages by Emerson College and Quinnipiac University compared to all other pollsters in the same state

StateQuinnipiac  Emerson 
California   29.328.60.8
Iowa   -0.40.5-0.9
Massachusetts   36.934.32.6
Montana   -12.1-6.1-5.9
Nevada   -0.16.0-6.1
New Hampshire   7.88.1-0.3
North Carolina   0.92.1-1.2
South Carolina-4.2-7.12.8   
AVERAGE All States3.5  -0.5
AVERAGE Ohio, Pennsylvania, Texas1.9  -0.7

However, using the same calculation method—except for ignoring partisan lean—the 20 Emerson polls conducted by Emerson give Biden “only” a 3.7-point lead, which is 5.3 points more Republican than the average of the other 612 polls. At the same time, the 13 Quinnipiac polls give Biden a 9.9-point lead, which is 1.0 points more Democratic than the average of the other 619 polls. Put another way, Quinnipiac polls “see” a race that is 6.3 points more favorable to Biden than Emerson polls do, though both give Biden a solid lead.

While national polls are interesting—and plentiful—it is the Electoral College that determines who wins presidential elections. Table 1 compares state-level presidential polling averages by Emerson and Quinnipiac, in states where they have assessed the presidential election at least twice, to those calculated by all other pollsters in the state; positive values indicate a Democratic lead or pro-Democratic bias, and negative values indicate the opposite. Emerson has conducted one poll of the presidential election in Florida, Georgia, New Mexico, New Jersey and South Carolina; Quinnipiac has conducted one poll of the presidential election in Colorado, Connecticut, Iowa, Michigan, New Jersey, New York and Wisconsin.

In the 13 states where Emerson has assessed the 2020 presidential election, the average bias is only 0.5 points towards Trump, fully 4.8 points lower than its national bias toward Trump. By contrast, in the eight states where Quinnipiac has assessed this election—five of them in the south, the average bias is 3.5 points toward Biden, 2.5 points higher than its national bias toward Biden. The gap between the two polling organizations also narrows from 6.3 to 4.0 points at the state level.

Notably, while Quinnipiac has an average bias toward Biden in all eight states—ranging from more than five points in Georgia, Maine and Florida to around one point in Ohio and Texas—Emerson’s bias is evenly split across its 13 multiple-assessment states, ranging from nearly six points towards Trump in the western states of Montana and Nevada to between two and four points toward Biden in the disparate states of Arizona, Massachusetts (where Emerson College is located) and Michigan.

Curiously, Emerson and Quinnipiac have both assessed the 2020 presidential election in only three states—Ohio, Pennsylvania and Texas—multiple times since January 1, 2019. In these three states, the bias is relatively narrow: Trump +0.7 for Emerson and Biden +1.9 for Quinnipiac, for a gap of “only” 2.6 points.


Turning to other statewide elections in 2020, Table 2 compares Senate election polling averages by Emerson and Quinnipiac, in states where they have conducted such polls at least twice since January 1, 2020, to those calculated by all other pollsters in the state. Emerson has conducted one Senate election poll in Georgia, assessing both seats on the ballot this year, as well as in Arizona, Iowa, Michigan, Minnesota, New Hampshire and New Jersey; Quinnipiac has conducted one Senate election poll in Iowa and Michigan. For the “jungle primary” in which Georgia Republican Senator Kelly Loeffler seeks reelection, I analyze the difference between the total percentage for all Democratic candidates and the total percentage for all Republican candidates.

Table 2: 2020 Senate and gubernatorial election polling averages by Emerson College and Quinnipiac University compared to all other pollsters in the same election

StateQuinnipiac  Emerson  
Montana   -8.4-0.8-7.6
North Carolina   2.65.1-2.4
South Carolina0.0-2.82.8   
AVERAGE  3.3  -5.0

In a reverse of state-level presidential election polling, Quinnipiac has assessed six Senate elections multiple times—again focusing on the south, while Emerson has only assessed Senate elections in Montana and North Carolina more than once; no Senate election has been polled multiple times by both pollsters. Quinnipiac has an average 3.3-point bias toward Democratic Senate nominees, nearly identical to its 3.5-point state-level presidential election bias. By contrast, albeit only in two Republican-leaning states, Emerson has an average 5.0-point bias toward the Republican Senate nominees, nearly identical to their Trump bias nationally, and fully 4.5 points higher than their state-level bias toward Trump. Overall, and recognizing this is not an apples-to-apples comparison, Quinnipiac Senate election polls lean 8.3 points more Democratic than Emerson Senate election polls.

Quinnipiac has been especially Democratic-leaning in Georgia’s two Senate elections, with average pro-Democratic-nominee biases of 6.2 and 7.2 points, and in Maine, while they have shown minimal bias in Kentucky and Texas. As with the presidential election, meanwhile, Emerson has a whopping 7.6-point bias toward incumbent Montana Republican Senator Steve Daines in his race against Democratic Governor Steve Bullock; they are relatively closer to the mark in North Carolina, where Democrat Cal Cunningham has a small lead against incumbent Republican Thom Tillis.

Quinnipiac has conducted no gubernatorial election polls this year, while Emerson has conducted one poll in New Hampshire and multiple polls in Montana (6.5 points more Republican) and North Carolina (7.4 points more Republican), with a large average pro-Republican bias of 6.9 points!


Table 3 lists the average partisan biases for Emerson and Quinnipiac for each set of races.

Table 3: Average partisan biases in Emerson College and Quinnipiac University polls across multiple election categories


While Quinnipiac has had only a relatively small pro-Biden bias in national polls, they have had an overall lean of 2.6 points Democratic across all elections they have assessed multiple times. By contrast, while Emerson has been very close to the all-polls average in their state-level presidential election polling, they have had an overall lean of 4.4 points Republican across all elections they have assessed multiple times. Overall, Quinnipiac has leaned fully 7.0 points more Democratic than Emerson has.

I will not attempt to “explain” these relative partisan biases, though they almost certainly result from some combination of how the demographic distribution of the likely 2020 electorate is modeled, the fact Quinnipiac shifted to “likely voters” models more recently than Emerson did, how hard they “push” initially undecided voters to choose one candidate, and the relative partisan leanings of demographic categories within their respective samples.

I will say, though, that the final Democratic-minus-Republican margin will almost certainly be very close to the midpoint of the two polling averages plus one point Democratic—at least in elections assessed at least once by Emerson and by Quinnipiac.

Until next time…please stay safe and healthy…and if you have not already voted, please do so as soon as you can!

2020 Senate and Gubernatorial Elections: The View from Labor Day

Democratic National Committee chair Tom Perez should be very pleased with his performance. Since winning the chairperson position in February 2017, he has overseen a net gain of eight gubernatorial elections and hundreds of state legislative seats, as well as winning back control of the United States House of Representatives (“House”) in 2018—flipping a historic net 41 seats. He also held net losses in the United States Senate (“Senate”) to one—helped Democrat Doug Jones’ upset win in Alabama in December 2017—when 2018 looked like a terrible year for Senate Democrats.

As of Labor Day 2020, meanwhile, the Democratic nominee for president—former Vice President Joseph R. Biden, Jr.—is in a very strong position, the House appears safe for Democrats…and Democrats are poised to add seats in the Senate, with control of the upper chamber for the first time since 2014 highly plausible.

Currently, there are 53 Republicans, 45 Democrats and 2 Independents who caucus with Democrats in the Senate. To regain control, Democrats must either win a net total of four Senate seats OR a net total of three Senate seats while winning back the presidency; as president of the Senate, Vice President Kamala Harris breaks a 50-50 tie.

In May 2019, I surveyed the 34 Senate races—now 35 with the December 2019 retirement of Republican Senator Johnny Isakson of Georgia and subsequent appointment of businesswomen Kelly Loeffler by Republican Governor Brian Kemp—scheduled for November 2020. I concluded then that while paths existed for the Democrats to recapture the Senate, everything would have to go just right.

More than one year later, based upon a political climate strongly favoring Democrats—they lead by 7.2 percentage points on the generic ballot[1]—and all publicly-available polls conducted since January 1, 2020, everything appears to be going right for the Democrats.

Before continuing, here is the September 2020 lighthouse photograph in my Down East 2020 Maine Lighthouses wall calendar.


Table 1 presents the 35 Senate races scheduled for November 2020, sorted by 3W-RDM, my measure of how much more or less Democratic a state votes relative to the nation. “National Lean” is the current generic ballot margin. “Incumbency” is the average electoral advantage adhering to reelection candidates, calculated separately by party and adjusted downward for serving less than one full six-year term. “Sum” is 3W-RDM plus Incumbency plus National Lean, or what I call the “fundamentals”: how a generic Democrat would expect to fare against a generic Republican in a state, all else being equal.

Table 1. 2020 Senate election overview

NameStateRun 20203W-RDMIncumbencyNational LeanSum
Edward MarkeyMAYes22.
Jack ReedRIYes18.
Richard DurbinILYes14.
Chris CoonsDEYes12.
Cory BookerNJYes12.
Jeff MerkleyORYes8.
Tom UdallNMNo6.
Gary PetersMIYes2.
Mark WarnerVAYes1.
Tina SmithMNYes1.
Jeanne ShaheenNHYes0.
Doug JonesALYes-
Susan CollinsMEYes5.9-
Cory GardnerCOYes2.2-
Joni ErnstIAYes-4.7-
Thom TillisNCYes-6.0-2.47.2-1.2
David PerdueGAYes-9.6-2.47.2-4.8
Kelly LoefflerGAYes-9.6-0.47.2-2.8
Martha McSallyAZYes-9.7-0.67.2-3.1
John CornynTXYes-15.3-2.47.2-10.5
Lindsey GrahamSCYes-15.7-2.47.2-10.9
Cindy Hyde-SmithMSYes-18.5-1.67.2-12.9
Steve DainesMTYes-18.6-2.47.2-13.8
Dan SullivanAKYes-19.2-2.47.2-14.4
Bill CassidyLAYes-22.2-2.47.2-17.4
Pat RobertsKSNo-
Lamar AlexanderTNNo-
Ben SasseNEYes-25.8-2.47.2-21.0
Mike RoundsSDYes-25.8-2.47.2-21.0
Tom CottonARYes-28.2-2.47.2-23.4
Mitch McConnellKYYes-28.7-2.47.2-23.9
James RischIDYes-34.2-2.47.2-29.4
Shelley Moore CapitoWVYes-35.5-2.47.2-30.7
James InhofeOKYes-38.1-2.47.2-33.3
Mike EnziWYNo-

Based solely on these fundamentals, only one Democrat—Jones—entered the 2020 election cycle in serious danger of losing her/his seat, while two Republican—four-termer Susan Collins of Maine and first-termer Cory Gardner of Colorado—were in a similarly weak position. First-termer Joni Ernst of Iowa is basically a 50-50 proposition, while first-termer Thom Tillis of North Carolina is only slightly ahead, as are two recently-appointed Senators, Loeffler and Martha McSally, who lost to Democrat Kyrsten Sinema in 2018; slightly further ahead, but “only” by 4.8 points is first-termer David Perdue of Georgia.

So, at least according to the fundamentals, Democrats entered the 2020 election cycle poised to net between one and six Senate seats, making control of the chamber slightly more likely than not to remain Republican.


Publicly-available polling tells a broadly similar story, even if the quantity and quality—based upon FiveThirtyEight’s pollster ratings—of polls varies widely from state to state:

Table 2: Number and Average Quality of 2020 Senate Election Polls

State# of PollsAverage Rating
North Carolina46B-/B
Georgia (Loeffler)31B/B-
Georgia (Perdue)16B
South Carolina10B-/B
New Hampshire5B-
New Jersey1A+
New Mexico1B
All other states0 

Only 22 races (63%) have been polled at all, with North Carolina (46), Michigan (42), Arizona (37) and the Loeffler race in Georgia (31) topping the list; six other states—the Perdue race in Georgia, Iowa, Kentucky, Maine, South Carolina and Texas—have been polled at least 10 times. Thus, just 11 races account for 227 (83%) of the 274 total Senate election polls conducted thus far in 2020.

Table 3 lists expected outcome, based on the fundamentals, and current weighted-adjusted polling average (WAPA) for each Democratic Senate nominee; New Hampshire will hold its Senate primaries on September 8, with incumbent Democratic Senator Jeanne Shaheen expected to win re-nomination easily. Elections with no incumbent are in italics.

Table 3: Expected and actual polling margins for 2020 Democratic Senate nominees, Labor Day 2020

StateExpectedWAPAExp – WAPA
Rhode Island29.6  
New Jersey23.621.7-1.9
New Mexico13.713.70.0
New Hampshire11.713.61.9
North Carolina-
South Carolina-10.9-4.16.8
South Dakota-21.0  
West Virginia-30.7  

* Only for the 22 states with both measures

The WAPA for New Hampshire is the average of polls assessing Shaheen against retired United States Army officer Donald J. Bolduc (12.5) and attorney Bryant “Corky” Messner (14.8); all five polls were conducted by the University of New Hampshire, a B- pollster with a prior Democratic lean of 2.8 points.

The Loeffler race is a “jungle” primary in which every candidate, regardless of party affiliation, will appear on the November 3 ballot; assuming no candidate tops 50%, a runoff election between the top two vote-getters will take place on January 5, 2021. Republican House Member Doug Collins of Georgia is also running, as are Democrats Raphael Warnock, senior pastor of Ebenezer Baptist Church in Atlanta, Matt Lieberman, son of 2000 Democratic vice-presidential nominee Joe Lieberman, and former United States Attorney Ed Tarver. WAPA combines polls of all candidates—which suggest Loeffler and Collins could be the top two vote finishers—and head-to-head matchups between each Republican and each Democrat. The latter show all three Democrats beating Loeffler, and all three losing to Collins—albeit based on only one or two polls. Overall, then, this is an extremely difficult election to assess.

The correlation between expected margin and WAPA is +0.92, meaning the polling is broadly in line with the underlying “fundamentals” of the election. Still, even in a strong Democratic year, Democratic Senate nominees are “overperforming” expectations by an average of 4.3 percentage points (“points”), at least in the 22 Senate elections with at least one poll.

Table 4, finally, shows the win probability for each Democratic nominee based upon fundamentals, current polling and a weighted combination of the two, as well as a final projected margin; for calculation details, please see here. Republican seats in which Democrats lead are in boldface, while Democratic seats in which Repubicans lead are in boldfaced italics.

Table 4: Estimated state margins and probability Democrat wins, 2020 Senate Elections

StateCurrent PartyP(D win): ExpectedP(D win): WAPAP(D Win): OverallPredicted Margin
MassachusettsDEM100.0% 100.0%33.7
Rhode IslandDEM100.0% 100.0%29.6
IllinoisDEM100.0% 100.0%26.3
New JerseyDEM99.9%100.0%100.0%22.3
DelawareDEM99.9% 99.9%24.1
OregonDEM99.7% 99.7%20.3
New HampshireDEM93.7%100.0%99.3%13.4
New MexicoDEM96.5%100.0%99.2%13.7
North CarolinaGOP39.1%94.4%88.6%4.1
South CarolinaGOP5.0%8.7%8.1%-5.1
LouisianaGOP0.5% 0.5%-17.4
TennesseeGOP0.3% 0.3%-18.6
NebraskaGOP0.1% 0.1%-21.0
South DakotaGOP0.1% 0.1%-21.0
ArkansasGOP0.0% 0.0%-23.4
IdahoGOP0.0% 0.0%-29.4
West VirginiaGOP0.0% 0.0%-30.7
WyomingGOP0.0% 0.0%-38.5

Two months before election day 2020, and with caveats about what voting will look like during a pandemic, Democrats are in a very strong position to recapture the Senate—albeit with few, if any, seats to spare.

Let us examine these 35 elections in groups.

Safe Democratic (9). Senators Edward Markey of Massachusetts, Jack Reed of Rhode Island, Richard Durbin of Illinois, Cory Booker of New Jersey, Chris Coons of Delaware, Jeff Merkley of Oregon, Mark Warner of Virginia and Shaheen should easily win reelection by double-digit margins, while in New Mexico House Member Ben Ray Lujan is expected to beat meteorologist Mark Ronchetti equally handily.

Lean/likely Democratic (2). The only reason first-term Senators Gary Peters of Michigan and Tina Smith of Minnesota are considered remotely vulnerable is the fact they represent two of the closest states in the 2016 presidential election, and because their polling averages are between four and five points below their election fundamentals. Still, each is very likely to prevail over businessman John James and former House Member Jason Lewis, respectively, by mid-single-digit margins.

Likely Democratic flips (4). Four incumbent Republican Senators—Gardner, McSally, Collins and Tillis—appear headed for defeat by single-digit margins. Gardner is the most likely to lose—by as much as 10 points—to former Governor John Hickenlooper. McSally is right behind, staring at a high-single-digit defeat by former astronaut Mark Kelly, husband of former Arizona House Member Gabrielle Giffords, who was shot and severely wounded in January 2011.

Collins and Tillis, meanwhile, trail Maine State House of Representatives Speaker Sara Gideon and former North Carolina State Senator Cal Cunningham, respectively, by around five points. While not guaranteed to win by any means—Collins won her last election by 37 points, and North Carolina leans 6.0 points Republican—right now these two states are likely Democratic pickups.

Toss-ups (2). Based solely on expectations—incumbent Republican in a lean-Republican state running for reelection in a strong Democratic year—Ernst is no more than even money to win reelection. And while she only trails businesswoman Theresa Greenfield by 1.3 points, that is enough to make Ernst the slightest of underdogs.

On the flip side is heavily Republican Montana, where Steve Daines seeks a second term. The fundamentals suggest Daines should easily win reelection by between 10 and 15 points. However, Governor Steve Bullock is mounting a very strong challenge, trailing by only 0.9 points overall—albeit a few points lower than when he declared his candidacy in early March.

Democrats could easily win both of these races, lose both of these races or split them, with Greenfield likelier to win than Bullock.

Likely Republican flip (1). While Jones is outpacing his fundamentals—running as a Democratic incumbent after only three years in a very Republican state—by 8.6 points, he remains very unlikely to prevail against former college football head coach Tommy Tuberville. In fact, losing “only” by single digits would be a moral victory.

Lean/likely Republican (6). Setting aside the Loeffler reelection, Democrats appear likely to fall short in Georgia’s other Senate election, Kansas, South Carolina, Alaska and Texas. Journalist Jon Ossoff, State Senator Barbara Bollier, former South Carolina Democratic Party Chair Jaime Harrison, orthopedic surgeon (and Independent) Al Gross, and United States Air Force veteran Mary Jennings “M. J.” Hegar, respectively, are overperforming expectations by an average 6.3 points against Senator David Perdue, House Member Roger Marshall and Senators Lindsey Graham, Dan Sullivan and John Cornyn. However, they are doing so in states which lean Republican by an average of 16.6 points.

Still, just as Republican upsets in Michigan and Minnesota cannot be ruled out, neither can Democratic victories in any of these states, with Ossoff likeliest to do so, followed by Harrison. And, in Texas, roughly 20% of voters in polls conducted in July and August are still undecided, which is a warning sign for any incumbent.

It is worth noting that a Harrison victory would give South Carolina two African-American Senators, which has not happened in any state since Reconstruction.

Likely Republican/Sleepers (2). In Mississippi, first-term Senator Cindy Hyde-Smith is again facing former Agriculture Secretary Mike Espy, who lost by only 7.2 points in 2018. One year later, Republican Tate Reeves defeated Democrat Jim Hood by only 5.5 points in an open gubernatorial election. Currently, Espy trails by 11.0 points, very close to the 12.9 points suggested by the fundamentals. Based on recent history, then, this race could yet tighten, though Hyde-Smith is still heavily favored.

In Kentucky, meanwhile, Republican Senate Majority Leader Mitch McConnell seeks a 7th term against former United States Marine fighter pilot Amy McGrath. The fundamentals say McGrath should be trailing by nearly 24 points. However, she is “only” down by 9.6 points, and in six polls conducted since June 1, 2020, she trails in three by 3-5 points and in three by 17-22 points, making this a very difficult race to assess. As with Espy, though, McGrath is highly likely to lose by mid-to-high single digits.

Safe Republicans (9). Senators Bill Cassidy of Louisiana, Ben Sasse of Nebraska, Mike Rounds of South Dakota, Tom Cotton of Arkansas, James Risch of Idaho, Shelley Moore Capito of West Virginia and James Inhofe of Oklahoma should easily win reelection by double-digit margins. And in Tennessee and Wyoming, respectively former United States Ambassador to Japan Bill Hagerty and former House Member Cynthia Lummis are expected to win by similar margins.

In sum, Democrats appear all but certain to net at least one Senate seat, losing in Alabama while winning in Arizona and Colorado, and are very well-positioned to win seats in Maine and North Carolina, giving them a 50-50 tie in the Senate—broken by Vice President Mike Pence or Harris. To be fair, though, it is difficult to see how Democrats win all four seats while losing the presidential election, so I assume Harris breaks the tie in this scenario.

The question, then, is whether Democrats can add further seats in Iowa, where they are slightly favored, and/or Montana, where they are slight underdogs…and possibly in Georgia, where Ossoff has a roughly 1-in-5 chance of winning. Democrats have further pickup opportunities in some Republican states, albeit with at most an 8% chance.

Bottom line: The most likely range of Democratic pickups is three to five, with a plausible range of one to six—exactly what the fundamentals suggested in May 2019. If I simply add up the probabilities Democrats win each race, they sum to +4.1, though this is very “back of the envelope” methodology.

Another way to think about these races is to observe how Democratic win probabilities change with either of two reasonable assumptions:

  1. All polls are overestimating Democratic margins by 3.0 points.

In this scenario, Democrats remain almost certain to win in Arizona (89.0%) and Colorado (95.5%) while losing in Alabama. Maine (61.1%) and North Carolina (67.1%) are now toss-ups, though Democrats would still be the slightest of favorites in both. But Iowa would now lean Republican (29.0%), with Democrats no more than an 8.5% favorite (Montana) anywhere else. Meanwhile, Democrats would still be favored in Minnesota (84.0%), but it would not be a comfortable lead.

Bottom line: Democrats could net zero seats, or they could net three seats, with a gain of one or two the likeliest outcome; summing the probabilities suggest a 2.3 seat gain, making Democrats modest underdogs to win back the Senate.

  • All polls are underestimating Democratic margins by 3.0 points.

While Alabama is still very likely to flip Republican, Democrats would be at least a 94% favorite to win Arizona, Colorado, Maine and North Carolina—and an 88.6% favorite to win Iowa—for a minimum net gain of four seats. Montana (65.3%) and the Perdue race in Georgia (53.4%) would be toss-ups, with Democrats the slightest of favorites, albeit by 0.2 points, suggesting long recounts in both states. Should Democrats prevail in both, that increases the net gain to six seats. And Democrats would now only be modest underdogs in toss-up races in Kansas (32.5%) and South Carolina (32.2%), with the difficult-to-assess Loeffler race in Georgia (27.2%) just beyond that. However, they would still be unlikely to win in Alaska (14.3%) or Texas (4.5%).

Bottom line: In this scenario, Democrats net four to eight seats, with five or six the likeliest outcome. Summing the probabilities, though, suggests a Democratic net gain of 6.1 seats, making them very strong favorites to win back the Senate.


Flying well under the radar are 11 states holding gubernatorial elections in 2020. Democrats are defending four of them; John Carney, Jay Inslee and Roy Cooper are all-but-guaranteed to be reelected in Delaware, Washington and North Carolina, respectively. The latter is somewhat surprising, given Cooper’s 0.2 point upset win over Republican incumbent Pat McCrory in 2016; the fundamentals suggest a 6.9-point lead, while the polls have him up 11.8 points—something in between these two seems likely.

The other governor’s mansion Democrats are defending is in Montana, where Bullock is stepping down after two terms (and running for the Senate). Montana leans 18.6 points more Republican than the nation, and Democrats Bullock and Brian Schweitzer have governed the state for 16 consecutive years, making it ready for a Republican flip; the fundamentals say House Member Greg Gianforte should win by 11.4 points. And while Democratic Lieutenant Governor Mike Cooney is “only” trailing by 5.8 points, that is not close enough to give Democrats more than a 2.8% chance of winning.

Six Republican governors, meanwhile, are running for reelection—and all are expected to win by at least 9.3 points. This includes heavily Democratic Vermont, where Phil Scott leads Lieutenant Governor David Zuckerman by 31.9 points, and partisan-neutral New Hampshire, where Chris Sununu leads both State Senate Majority Leader Dan Feltes and Executive Council of New Hampshire member Andru Volinsky by more than 30 points. The other four are Eric Holcomb in Indiana, Mike Parson in Missouri, former Democrat Jim Justice in West Virginia and Doug Burgum in North Dakota. In Utah, finally, Gary Herbert is stepping down after eight years; Republican Lieutenant Governor Spencer Cox is a near-lock to hold the governor’s mansion against Democratic law professor Christopher Peterson.

Bottom line: Even if one assumes polls are over- or under-estimating Democratic strength by three points, Montana is still the only state likely to flip partisan control—from Democratic to Republican. In fact, across all three scenarios, the range of “summed probabilities” is -0.50 to -0.76, with only the strong Democratic lean of Vermont keeping it even that close to no net change.

Until next time…please stay safe and healthy…

[1] That is, some variant of “If the election for United States House of Representatives was held today, would you vote for the Democrat or the Republican in your Congressional district?”

Biden vs. Trump September 2020: A rising tide lifts more than enough boats

On November 3, 2020, the presidential election between incumbent Republican Donald J. Trump and his Democratic challenger, former Vice President Joseph R. Biden, Jr., will mark the end of a weeks-long electoral process. One month ago, I analyzed all publicly-available polls of the presidential election—nationally and by state, recognizing presidential elections are determined by the Electoral College—conducted since January 1, 2019.

Since then, Biden selected United States Senator Kamala Harris of California to be his vice-presidential running mate, as I anticipated, and both the Democrats and Republicans held mostly-virtual televised nomination conventions.

Did these events change the trajectory of this election?

The short answer is…no.

Table 1 lists the number of national polls assessing Biden vs. Trump conducted in 2019 and in each month of 2020; a handful of older polls were released since my last update. Sixty-five pollsters, with an average B- FiveThirtyEight pollster rating, have assessed the 2020 presidential election at least once since January 1, 2019; 45 of them (mean B-/B) have assessed the election more than once.

Table 1: Number of 2020 Monthly National Polls Assessing Biden vs. Trump

Month# Polls
All of 2019107
January 202020
February 202025
March 202035
April 202050
May 202048
June 202062
July 202051
August 202073[1]

Fifteen pollsters (mean B-) account for 70% of these polls, as well as 68% of the 364 polls conducted in 2020:

  • YouGov (B-), 64 polls (49 in 2020)
  • Morning Consult (B/C), 48 polls (43 in 2020)
  • Ipsos (B-), 35 polls (28 in 2020)
  • HarrisX (C), 27 polls (18 in 2020)
  • Emerson College (B+), 19 polls (7 in 2020)
  • Fox News (A-), 18 polls (9 in 2020)
  • Change Research (C-), 16 polls (13 in 2020)
  • RMG Research (B/C), 15 polls (15 in 2020)
  • Data For Progress (B-), 14 polls (14 in 2020)
  • Optimus (B/C), 14 polls (13 in 2020)
  • IBD/TIPP (A/B), 14 polls (9 in 2020)
  • Rasmussen Reports/Pulse Opinion Research (C+), 13 polls (10 in 2020)
  • Quinnipiac University (B+), 11 polls (7 in 2020)
  • Zogby Interactive/JV Analytics (C+), 11 polls (6 in 2020)
  • CNN/SSRS (B/C), 10 polls (7 in 2020)

Figure 1 shows how Biden has fared monthly against Trump in 2020, using my weighted-adjusted polling averages (WAPA). I use pollster rating data to adjust for partisan lean (historic tendency to err more Democratic or Republican than other pollsters in analogous races) and quality. I weight more recent polls higher, using this ratio: number of days since January 1, 2019 divided by 673, the number of days between January 1, 2019 and November 3, 2020. I then average two versions of WAPA: one treating polls by the same pollster as statistically independent, and one treating all polls by the same pollster as a single, time-weighted value; differences between estimates are usually negligible.

Figure 1

Using all polls conducted since January 1, 2019, Biden leads Trump nationally by 7.5 percentage points (“points”). Biden’s margin rose from just over four percentage points in January and February, when he was fighting for the 2020 Democratic presidential nomination, to just under six points in the three months after Biden’s decisive win in the 2020 South Carolina Democratic presidential primary, to between eight and nine points since June 1, the day protesters were forcibly cleared from Lafayette Square so Trump could pose in front of St. John’s Episcopal Church holding a copy of the Bible.


Again, though, presidential elections are fought across 50 states and the District of Columbia (“DC”), with the plurality winner in each state/DC winning every electoral vote (“EV”) from that state. Table 2 lists the number of polls within each state assessing Biden vs. Trump since January 1, 2019, plus that state’s 3W-RDM, my estimate of much more or less Democratic than the nation a state has voted over the last three presidential elections; eight states[2] and DC have not been polled.

Table 2: Number of state-level polls assessing Biden vs. Trump since January 1, 2019

North Carolina-6.06956
New Hampshire0.11510
South Carolina-15.7108
New York21.677
New Jersey12.066
North Dakota-29.442
New Mexico6.533
West Virginia-35.511

Nineteen states have been polled at least 10 times since January 1, 2019, of which 14 have been polled at least 10 times in 2020. Four of the top five, along with suddenly-swing North Carolina, are the closest states won by Trump in 2016: Michigan, Wisconsin, Pennsylvania, Florida. Five other Republican-leaning states have been frequently polled: Arizona, Georgia, Texas, Ohio and Iowa, reflecting their status as ongoing or emerging battlegrounds. California, with 54 EV, rounds out the 11 states polled at least 20 times overall.

National averages still matter, though. Combined with 3W-RDM, they provide the “expected Democratic-minus-Republican margin” in each state in 2020, all else being equal. For example, North Carolina has recently been 6.0 points less Democratic than the nation as a whole. Adding that to Biden’s current national margin (-6.0 +7.5 = +1.5) suggests Biden is slightly favored to win North Carolina in 2020, based solely on its recent voting history. Indeed, Biden leads Trump by an adjusted mean of 1.9 points in 52 polls conducted in North Carolina. Table 3 lists every state’s expected value and WAPA.

Table 3: Expected and actual polling margins for Biden over Trump in each state in November 2020

New York21.629.125.9-3.2
Rhode Island18.025.5  
New Jersey12.019.518.2-1.3
New Mexico6.514.011.3-2.7
New Hampshire0.17.65.2-2.4
North Carolina-
South Carolina-15.7-8.2-7.30.9
South Dakota-25.8-18.3  
North Dakota-29.4-21.9-20.41.5
West Virginia-35.5-28.0-34.3-6.3

* Only for the 42 states with both measures

The correlation between the expected margin and WAPA is +0.961, meaning polling matches expectations extremely well—as one increases or decreases, so does the other. Still, Biden is polling slightly ahead of those fundamentals, meaning state-level polling as a whole is even better for Biden than his excellent national polling; that said, the difference vanishes once you adjust for a state’s 2016 presidential election turnout.[3]

Biden is underperforming expectations in some states, most notably Hawaii—the birthplace of former President Barack Obama, artificially inflating Hawaii’s Democratic vote margin in 2008 and 2012. He is also underperforming in woefully-under-polled Nevada. Biden leads there by 3.8 points, nearly six points lower than the 9.5 points by which he “should” be leading. Biden is also underperforming expectations in very Democratic Maryland (-5.5) and Republican-leaning Iowa (-4.4). By the same token, Biden is overperforming in the traditionally Republican states of Arkansas, Utah, Oklahoma, Alaska, Texas and Kansas, as well as in reliably-Democratic Washington. There is a partisan split in Biden’s over-and under-performance: in states with 3W-RDM>-5.0, Biden is underperforming by 2.2 points, on average. In states with 3W-RDM≤5.0, Biden is overperforming by 3.4 points. Many grains of salt are in order here, though. In recent elections, “fundamentals” have missed the final margin by an absolute value average of 5.4 points.

Still, the close alignment between the two values allows us to combine them into a single estimate of Biden’s margin over Trump on November 3, 2020, assuming polls become more predictive as an election gets closer:

  1. Assign expected value and WAPA equal weight as of January 1, 2020.
  2. WAPA weight increases daily with proximity to November 3, 2020.

I also calculated how likely Biden is to win the EV from each state, assuming this likelihood is distributed normally:

  1. For expected margins, I use mean = -0.8 and standard error = 7.1[4]
  2. For WAPA, I use standard error = 3.0, roughly the margin of error in most quality polls; this is likely an over-estimate, as pooling reduces the standard error of the resulting polling average.
  3. Combined probability Biden wins a state’s EV calculated the same as for predicted final margin

While the means and standard errors I use are arguably arbitrary, albeit defensible, the final EV probabilities shown in Table 4 are in line with what other forecasters are saying.

Table 4: Estimated final state margins and probability of winning EV, Biden vs. Trump, November 2020

StateEVP(EV): ExpectedP(EV): WAPAP(EV): OverallPredicted Margin
DC3100.0% 100.0%89.5
Vermont3100.0% 100.0%35.2
New York29100.0%100.0%100.0%26.3
Rhode Island4100.0% 100.0%25.5
Illinois2099.9% 99.9%22.2
New Jersey1499.6%100.0%99.9%18.8
Oregon798.5% 98.5%16.2
New Mexico596.8%100.0%99.3%11.9
New Hampshire483.1%96.0%94.3%5.5
North Carolina1554.0%73.6%71.6%1.9
South Carolina910.4%0.8%2.2%-7.4
Nebraska50.4% 0.4%-18.3
South Dakota30.4% 0.4%-18.3
North Dakota30.1%0.0%0.0%-21.0
Idaho40.0% 0.0%-26.7
West Virginia50.0%0.0%0.0%-31.2
Wyoming30.0% 0.0%-38.2
  • He is at least an 88.1% favorite in enough states—and by margins of at least four points—to earn him 308 EV, or 307 depending on what happens in Maine, which, along with Nebraska, allocates two EV to the statewide winner and one each to the winner of its Congressional districts. Moreover, Biden could lose Florida (+4.0, 88.1%), Nevada (+4.4, 89.4%) and one EV in Maine and still win 272 EV, two more than he needs.
  • He is a 70-75% favorite to win in Arizona (+2.4) and North Carolina (+1.9), for an additional 26 EV, increasing Biden’s total to 333/334 EV.
  • The 34 combined EV of Ohio (+0.6) and Georgia (-0.8) are essentially toss-ups, meaning Biden has a roughly 73% chance to win at least one of them, putting him somewhere between 349 and 352 EV, with a maximum of 368 EV (or 369 with one EV in Nebraska).

Three months before Election Day 2020, and with every caveat about voting during a pandemic, Joe Biden is the strong favorite to be elected the 46th president of the United States.

Plus, it might take only a sharp break by undecided voters and a modest polling error for Biden to win the 44 combined EV of Iowa (-0.9) and the ultimate prize—Texas (-2.7). Thus, while something in the low-to-mid 300’s currently appears the most likely EV total for Biden, 413 EV cannot be discounted.

Using the simplistic—perhaps even simple-minded—method of multiplying Biden’s probability of winning each state by its EV and summing yields a “projected” EV total of 349.2, essentially adding Michigan, Pennsylvania, Wisconsin, Florida, Arizona, North Carolina, and one of Ohio/Georgia to the states 2016 Democratic presidential nominee Hillary Clinton won.

Biden’s lead looks even more robust when you make either of two historically-valid assumptions:

Polls systematically overestimate Biden’s margins by 3.0 points.

In this scenario, Biden’s projected EV drops to 301.2, still 31.2 more than required. He would be favored at least 80% to win in enough states to win 239 EV, though he would also be favored by at least 74.6% in three states totaling 34 EV, getting him to 273 EV. Thus, even if Biden “only” wins the national popular vote by 4.2, he would likely still prevail, though the decisive states—some combination of New Hampshire, Pennsylvania and Wisconsin—would be decided by narrow margins, with all votes possibly not counted for a week or more.

Polls systematically underestimate Biden’s margins by 3.0 points.

In this scenario, Biden’s projected EV are a landslide-level 389.4, 119.4 more than necessary. He would be favored at least 80% to win enough states to earn 352 EV, while being a 74.9% favorite in Georgia, for a total of 368 EV. He would also be a 69.1% favorite in Iowa, with Texas now a toss-up at 58.1%–and a projected Biden victory of 0.3 points! Based on only one poll, Biden would have a 33.2% chance of winning Arkansas’ 6 EV, plus a 14.3% chance of winning Missouri’s 10 EV and a 11.5% chance of winning Alaska’s 3 EV. The last presidential candidate to come close to 433 EV was Republican George H. W. Bush, who won 426 EV in 1988.


To maximize the number of polls available for analysis, I use all polls going back to January 1, 2019; I also use a straightforward time-weighting method: increasing the weight of a poll by 1/673 = 0.0015 every day since then.

To test the validity of this weighting system, I re-estimated every WAPA and probability using the following time-weighting system, based on the key dates of February 29 and June 1 described above:

  1. Only use polls whose field date midpoint is January 1, 2020 or later (that is, date weight for 2019 polls = 0)
  2. Weight polls released in January and February 2020 as before
  3. Weight polls released in March, April and May 2020 twice as much as before
  4. Weight polls released in June, July and August 2020 three times as much as before
  5. Weight polls in September and October 2020 four times as much as before

This system gives vastly more weight to the most recent polls and correspondingly much lower weight to earlier polls.

As one would expect from Figure 1, Biden’s national lead jumps to 8.0 points using this time-weighting method, though the projected EV total barely increases to 351.4, with only minor changes in the probability Biden wins any given state: Nevada (92.3% and Florida (90.7%) rise slightly, while Ohio (52.2%) and Georgia (40.1%) decline slightly.

However, state-level changes in WAPA are very telling, as Table 5 reveals:

Table 5: 2020 Polling Margins, Biden vs Trump, Using Two Time-Weighting Methods

StateWAPA Original Time-WeightWAPA Recent Time-WeightDelta
New York25.8927.031.15
New Jersey18.2018.220.02
New Mexico11.3011.770.47
New Hampshire5.246.100.86
North Carolina1.892.150.26
South Carolina-7.25-6.620.63
North Dakota-20.42-19.131.28
West Virginia-34.30-34.300.00

Extending WAPA to two decimal places, Biden’s national lead increases by 0.46 points, from 7.50 to 7.97. However, rather than Biden increasing his lead by four or five points in some states, say, while decreasing his lead by three or four points in other states, only five states saw a decline in Biden’s average polling margin—Maryland, Georgia, Ohio, Kentucky and Utah; no decline was less than -0.77. And in only six states—Colorado, New York, North Dakota, Virginia, Washington and California—did Biden’s average polling margin increase by more than 1.00 points, with a maximum of 1.55. The standard deviation of the average change in Biden’s margin is only 0.55, showing how tightly bunched around the mean of 0.40 points these shifts are.

In other words, when switching to a time-weighting method which gives vastly more weight to polls released over the preceding three months while eliminating 2019 polls entirely, Biden saw his lead either not change or increase by up to 0.94 in 31 of 42 states. This remarkably consistent change should alleviate fears that Biden will win the popular vote by four or five points, yet still lose the Electoral College because he won even more votes than Clinton in safe states like California and New York while narrowing the 2016 margins in states like Georgia, Ohio and Texas without actually winning any of their EV. Instead, as Biden’s national margin increases, his lead in nearly every state—including nearly every swing state—increases correspondingly. Put differently, the same groups of voters fueling increases in Biden’s vote total in one set of states are also fuel increases in states like Michigan, Wisconsin, Pennsylvania and Florida—and perhaps Arizona and North Carolina as well.

Figure 2 makes this same point in a different way. It compares current Biden WAPA to simply increasing every 2016 Democratic margin increased by 5.4 points, the difference between Biden’s current national polling lead and the 2.1 points by which Clinton won in 2016.

Figure 2

Figure 2 perfectly illustrates the adage “A rising tide lifts all boats,” or nearly all, anyway. Biden’s current state-level polling averages—as I calculate them—are astonishingly close to how you would expect him to fare in each state given a 5.4-point increase in the national Democratic margin.


None of this is to say Biden is guaranteed to be elected president of the United States on in two months. There are worrisome signs this year’s elections will not be conducted as efficiently and transparently as they could be. Delays in mail delivery—allegedly orchestrated by a newly-confirmed Postmaster General—could leave millions of votes uncounted because they did not arrive by November 3. Moreover, while Biden’s national polling lead has consistently ranged between four and 10 points over the last 20 months, a late-recovering economy or last-minute “October surprise” could erase this lead.

All that being said, however, unlike Clinton in 2016, Biden has a sufficiently-wide range of paths to 270 EV that I estimate he is at least an 80% favorite to be elected president of the United States on November 3, 2020—or whenever ballots are ultimately counted.

Until next time…please stay safe and healthy…

[1] Includes one Redfield & Wilton Strategies poll conducted August 31 to September 1

[2] DC, Vermont, Rhode Island, Illinois, Oregon, Nebraska, South Dakota, Idaho, Wyoming

[3] That said, this does not account for mid-to-large states like Oregon and Illinois where Biden is expected to win by double-digit margins.

[4] The former value is the mean arithmetic difference between “expected” and actual D-R margins across 153 state-level contests in 2008, 2012 and 2016, while the latter value is the standard deviation of these values. I recognize this is not a standard error. However, using the value 13.6—the range of values covering 95% of all values divided by 1.96, the final EV projection changes by only 1.0.

An update on Emerson College polling

In two essays I published in November 2019 (here and here), I addressed differences between polling results obtained by highly-respected Emerson College and those from other pollsters in the same race. Emerson College has an A- rating from FiveThirtyEight.com, and their analysts calculate that, on average, Emerson College polls are about 0.3 points more Democratic than other pollsters in the same elections.

Emerson College recently released new national and state-level polls, renewing interest in their work. I therefore decided to update my assessment by comparing Emerson College polls to those released by other pollsters in the same races, using all publicly-available polls released since January 1, 2019.

I Voted sticker

I begin with national polls of the 2020 presidential election between Democrat Joseph R. Biden, Jr., the former Vice President, and Republican incumbent Donald J. Trump. The 18 polls Emerson College has released of this race, weighted by time, average to a Biden lead of 3.6 percentage points (“points”) over Trump; this increases to 3.9 if I do not adjust for Emerson’s calculated Democratic lean. By comparison, the other 370 polls of this race—using my weighted-adjusted polling average (WAPA)—give Biden a 7.4-point lead, with essentially no partisan lean. That is, relative to other polls assessing Biden vs. Trump nationally, Emerson College polls are 3.5-3.8 points more Republican.

Table 1 repeats this comparison for every state in which Emerson College has polled the presidential election at least twice since January 1, 2019; the month of the most recent Emerson College poll is also listed. States are sorted by number of Emerson College polls and poll recency.

Table 1: Comparing state-level WAPA, Biden vs. Trump, Emerson College to all other pollsters

State # Emerson Polls Emerson College All Other Pollsters Emerson minus Other
Iowa 4


-1.8 -2.2 D+0.4
Texas 3


-1.4 -2.1 D+0.7
New Hampshire 3


6.7 4.7 D+2.0
Massachusetts 2


34.4 30.6 D+3.8
Ohio 2


-0.4 1.0 D-1.4
California 2


29.3 27.6 D+1.9
Michigan 2


11.0 7.0 D+4.0
Nevada 2


-0.4 +4.6 D-4.2
TOTAL/AVERAGE 20 9.7 8.9 D+0.8
Weighted by # polls 20 7.8 7.0 D+0.8

These eight states tell a very different story. On average, these polls show an average 0.8 points more support for Biden than all other polls in these states, irrespective of the number of polls Emerson College has conducted in that state. One major caveat is that Emerson College has yet to conduct a presidential horse race poll in calendar year 2020 in four of these states. If anything, though, state-level Emerson College polls of Biden vs. Trump have become more Democratic leaning: the four states with no calendar year 2020 polls show a Democratic lean of 0.45, broadly similar to the FiveThirtyEight estimate of 0.3, compared to 1.25 for the four states with a May 2020 Emerson College poll. Remove Massachusetts (home to Emerson College), however, and the difference vanishes.

I will post my assessment of polling in 2020 election for United States Senate (“Senate”) and governor around Labor Day; this assessment will only use polls released since January 1, 2020. At this point, though, Emerson College has released only two polls, in total, of any of this year’s 35 Senate and 11 gubernatorial elections. Both were conducted in Montana with 531 likely voters between July 31 and August 2, 2020. In the Senate race, Democratic Governor Steve Bullock trails incumbent Republican Steve Daines 44-50. The other six polls of this election give Bullock a narrow 0.9-point lead, for a pro-Republican lean of 6.9 points. Similarly, in the open governor’s race, Democratic Lieutenant Governor Mike Cooney trails Republican United States House of Representatives member Greg Gianforte 41 to 50; three other polls have Cooney down by 5.2 points, for a pro-Republican lean of 3.8 points. With all necessary caveats for small numbers, the average pro-Republican bias in these two polls is 5.4.

Curiously, while Emerson College presidential election polls force respondents to choose only between Biden and Trump—meaning their vote shares sum to 100%–in the two recent Montana polls, an average 7.5% of respondents chose an option besides the named Democrat and named Republican.

Still, this does not explain why, at the national level, Emerson College 2020 presidential election polls lean 3.5-3.8 points more Republican, while the sparse state-level polling leans 0.8 points more Democratic. Splitting the difference implies an Emerson College pro-Republican lean of about 1.4 points, but I would like to see far more state-level polling to have any confidence in that value.

Until next time…please stay safe and healthy…