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
DC3Biden86.886.6-0.2
Vermont3Biden26.435.49.0
Massachusetts11Biden27.233.05.8
Maryland10Biden30.032.52.5
California55Biden26.429.63.2
Hawaii4Biden32.229.5-2.7
Rhode Island4Biden15.520.85.2
Connecticut7Biden13.620.16.7
Washington12Biden15.719.33.6
Delaware3Biden11.319.07.7
Illinois20Biden14.016.62.6
Oregon7Biden11.016.25.2
New Jersey14Biden16.915.5-1.4
New York29Biden22.513.7-8.8
Colorado9Biden4.913.58.6
New Mexico5Biden8.210.82.6
Virginia13Biden3.010.16.9
Maine4Biden (3)5.38.73.4
New Hampshire4Biden0.47.47.0
Minnesota10Biden1.57.15.6
Michigan16Biden-0.22.62.8
Nevada6Biden2.42.40.0
Pennsylvania20Biden-0.71.01.7
Wisconsin10Biden-0.80.61.4
Georgia16Biden-5.10.35.4
Arizona11Biden-3.50.33.8
North Carolina15Trump-3.7-1.42.3
Florida29Trump-1.2-3.4-2.2
Texas38Trump-9.0-5.73.3
Ohio18Trump-8.1-8.2-0.1
Iowa6Trump-9.4-8.21.2
Alaska3Trump-14.3-10.13.3
South Carolina9Trump-20.4-11.78.7
Kansas6Trump-18.5-15.13.4
Missouri10Trump-19.0-15.63.4
Indiana11Trump-20.2-16.14.1
Montana3Trump-14.7-16.4-1.7
Mississippi6Trump-25.1-17.87.3
Louisiana8Trump-19.6-18.61.0
Nebraska5Trump (4)-17.8-19.2-1.4
Utah6Trump-17.9-20.2-2.3
Tennessee11Trump-31.8-23.38.5
Alabama9Trump-26.0-25.60.4
Kentucky8Trump-27.7-26.01.7
South Dakota3Trump-29.8-26.23.6
Arkansas6Trump-29.8-27.62.2
Idaho4Trump-26.9-30.8-3.9
Oklahoma7Trump-36.4-33.13.3
North Dakota3Trump-35.7-33.42.4
West Virginia5Trump-41.7-39.02.7
Wyoming3Trump-46.3-43.42.9
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
Michigan-10,704+144,532+155,236
Pennsylvania-44,284+68,903+113,187
Wisconsin-22,748+20,510+43,258
Arizona-91,234+10,457+101,691
Georgia-212,141+14,155+226,296
TOTAL-381,111+258,557+639,668

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   
Bucks+2,699+17,415+14,716
Chester+25,568+53,598+28,030
Delaware+66,735+87,066+20,331
Montgomery+93,351+133,343+39,992
TOTAL+188,353+291,422+103,069
    
Major Urban   
Philadelphia+475,277+457,649-17,628
Allegheny+108,137+146,706+38,569
TOTAL+583,414+604,355+20,941
    
All Other Counties-816,051-826,874-10,283
TOTAL-44,284+68,903+113,187

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
Wyoming3Trump-32.1-43.4-11.3
South Dakota3Trump-15.6-26.2-10.6
North Dakota3Trump-23.2-33.3-10.1
Montana3Trump-7.1-16.4-9.3
Kentucky8Trump-17.2-26.0-8.8
Oklahoma7Trump-24.9-33.1-8.2
Texas38Trump1.6-5.7-7.3
Utah6Trump-12.9-20.2-7.3
Alabama9Trump-18.6-25.6-7.0
Indiana11Trump-9.6-16.1-6.5
Tennessee11Trump-16.9-23.3-6.4
Nevada6Biden8.62.4-6.2
Missouri10Trump-9.6-15.6-6.0
Kansas6Trump-10.2-15.1-4.9
Idaho4Trump-26.0-30.8-4.8
New Jersey14Biden19.515.5-4.0
Maine4Biden (3)12.58.7-3.8
Mississippi6Trump-14.1-17.8-3.7
Florida29Trump0.2-3.4-3.6
Alaska3Trump-6.7-10.1-3.4
Iowa6Trump-5.0-8.2-3.2
Connecticut7Biden23.020.1-2.9
Louisiana8Trump-15.8-18.6-2.8
South Carolina9Trump-8.9-11.7-2.8
Wisconsin10Biden3.20.6-2.6
Arizona11Biden2.90.3-2.6
Washington12Biden21.719.3-2.4
Hawaii4Biden31.629.5-2.1
Ohio18Trump-6.2-8.2-2.0
Michigan16Biden4.42.6-1.8
New Hampshire4Biden8.97.4-1.5
Nebraska5Biden (4)-17.8-19.2-1.4
Massachusetts11Biden34.333.0-1.3
Oregon7Biden17.516.2-1.3
New Mexico5Biden12.010.8-1.2
Pennsylvania20Biden2.21.0-1.2
Delaware3Biden20.219.0-1.2
Virginia13Biden11.210.1-1.1
Minnesota10Biden7.97.1-0.8
Georgia16Biden0.60.3-0.3
North Carolina15Trump-1.1-1.4-0.3
Illinois20Biden16.216.60.4
California55Biden29.129.60.5
Arkansas6Trump-29.1-27.61.5
Maryland10Biden30.231.91.7
Rhode Island4Biden19.020.71.7
Colorado9Biden11.413.52.1
Vermont3Biden28.835.46.6
DC3Biden74.986.611.7
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
OpiniumC+14.1-10.5
NORC (AllAdults only)C+11.3-7.7
CNN/SSRSB/C11.1-7.5
QriouslyC+10.5-6.9
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
SurveyUSAA8.8-5.2
IpsosB-8.5-4.9
LégerC+8.4-4.8
Change ResearchC-8.3-4.7
Fox NewsA-8.3-4.7
YouGovB8.2-4.6
Research Co.B-7.8-4.2
PureSpectrumC+7.6-4.0
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
IBD/TIPPA/B5.5-1.9
Emerson CollegeA-3.8-0.2
Zogby*C+3.60.0
Rasmussen Reports/Pulse Opinion ResearchC+3.20.4
CiviqsB/C3.10.5
AverageB/B-8.2-4.5

           * 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
MassachusettsMarkey28.532.94.4
DelawareCoons18.921.52.6
OregonMerkley15.117.62.5
IllinoisDurbin21.116.9-4.2
New JerseyBooker18.415.8-2.6
New HampshireShaheen6.515.79.2
VirginiaWarner7.912.04.1
ColoradoHickenlooper1.89.37.5
New MexicoLujan8.56.1-2.4
MinnesotaSmith5.75.2-0.5
ArizonaKelly-8.32.410.7
MichiganPeters8.61.5-7.1
Georgia Special???-8.0-1.07.0
Georgia???-10.0-1.78.3
North CarolinaTillis-6.4-1.74.7
IowaErnst-5.1-6.6-1.5
MaineCollis5.5-8.9-14.4
TexasCornyn-15.7-9.85.9
MontanaDaines-19.0-10.09.0
South CarolinaGraham-16.1-10.35.8
MississippiHyde-Smith-18.1-11.26.9
KansasMarshall-21.4-11.99.5
AlaskaSullivan-19.6-12.96.7
KentuckyMcConnell-29.1-19.59.6
AlabamaTuberville-24.2-20.63.6
LouisianaCassidy-22.6-25.9-3.3
TennesseeHagerty-23.8-27.1-3.3
IdahoRisch-34.6-29.35.3
OklahomaInhofe-38.5-30.28.3
South DakotaRounds-26.2-31.5-5.3
ArkansasCotton-28.6-33.3-4.7
NebraskaSasse-26.2-41.3-15.1
West VirginiaCapito-35.9-43.3-7.4
WyomingLummis-43.7-46.1-2.4
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
WyomingLummis-30.2-46.1-15.9
MaineCollins3.3-8.9-12.2
South DakotaRounds-19.9-31.5-11.6
NebraskaSasse-30.8-41.3-10.5
KentuckyMcConnell-9.7-19.5-9.8
OklahomaInhofe-20.5-30.2-9.7
AlaskaSullivan-3.7-12.9-9.2
AlabamaTuberville-11.5-20.6-9.1
New JerseyBooker24.615.8-8.8
MontanaDaines-1.3-10.0-8.7
DelawareCoons29.621.5-8.1
TexasCornyn-2.3-9.8-7.5
IllinoisDurbin23.716.9-6.8
KansasMarshall-5.4-11.9-6.5
South CarolinaGraham-4.7-10.3-5.6
TennesseeHagerty-21.9-27.1-5.2
MississippiHyde-Smith-6.4-11.2-4.8
ArizonaKelly6.62.4-4.2
New MexicoLujan10.06.1-3.9
Georgia???1.7-1.7-3.4
MichiganPeters4.71.5-3.2
IdahoRisch-26.1-29.3-3.2
MinnesotaSmith8.45.2-3.2
VirginiaWarner15.112.0-3.1
IowaErnst-3.6-6.6-3.0
North CarolinaTillis1.1-1.7-2.8
OregonMerkley20.017.6-2.4
ArkansasCotton-33.0-33.3-0.3
ColoradoHickenlooper9.39.30.0
MassachusettsMarkey31.432.91.5
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.

Summary

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.

3 thoughts on “2020 Elections Post-Mortem

    1. You are welcome. I **may** write something about the Georgia Senate runoffs, though I am a bit politics-out. So more likely why I think Steven Moffat was trolling fans in Doctor Who Series 8. Or, I could simply finish my book, then get it published. 🙂

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