2018 Election Cheat Sheet: How did I do?

I should apologize to our younger daughter’s friend’s mother.

In my…determination…to be settled in front of the television with snacks and beverages at precisely 6 pm EST on November 6, 2018, I might have been a bit abrupt collecting our youngest daughter from a local taqueria where said friend’s mother had generously taken them to supper (after schlepping them and one other girl back from gymnastics class).

However, thanks to help from the same daughter, I was at my post at the appointed time. Our youngest daughter even carefully picked out all of the red M&M’s (plain and peanut) from their decorative bowls. There were no red cashews to extract (but they were still delicious).

I also had a blue mechanical pencil to mark my 2018 Election Guide, as well as an entire 12-pack of unflavored Polar Seltzer cans sitting on the floor to my left (as the evening turned into midnight and beyond, the line of empty blue cans on the floor emanating from the carton grew longer and longer).

And sitting within reaching distance of my right arm was this colorful fowl.


You know it is a celebration in our home when “the rooster” makes an appearance. Rather than ice water, however, this evening it was filled with blue lagoons—which my wife Nell still cannot decide more closely resembles Windex or Scope.

As the early returns from Indiana and Kentucky were being tabulated on MSNBC, however, a sinking feeling set in that I would not be drinking as much of this cocktail as I had anticipated. I remembered from 2008 that Indiana’s Democratic pockets report much later than its eastern-half Republican counties, but Democratic Senator Joe Donnelly was trailing by well over 20 percentage points in a race that both FiveThirtyEight.com and I had labeled “Lean Democratic.” (Republican Mike Braun would eventually defeat Donnelly by 5.9 percentage points [points]) And Democrat Amy McGrath was not faring as well in the early tallies from the 7th Congressional District (CD) in Kentucky against incumbent Republican Andy Barr as I had hoped. (McGrath would eventually lose by 3.2 points.)

When polls closed at 7 pm EST in Vermont and Virginia, MSNBC almost immediately projected wins in their respective United States Senate (Senate) races for Independent Bernie Sanders and Democratic Senator Tim Kaine—meaning that the first calls of the night were for men I had voted for in 2016 in completely different contexts—Sanders in the Massachusetts Democratic Presidential Primary and Kaine as the Democratic nominee for vice president.

That sinking feeling only grew worse as the FiveThirtyEight.com “live tracker” of Democrats’ chances of regaining control of the United States House of Representatives (House) dipped below 50% around 8:30 or so. Nell, worried, yelled into the living room, “I am not hearing any whoops or cheers.”

At just before 9 pm (when it was already clear Republicans would not only maintain control of the Senate but add seats), the indefatigable Steve Kornacki  announced NBC was giving the Democrats only a 65% chance of regaining the House, projecting they would finish with between 216 (2 too few) and 232 House seats; this translates to a net gain of between 21 and 37 seats.

Finally, however, as votes were counted in Virginia and, especially, New York, both the FiveThirtyEight.com tracker and the NBC “big board” manned brilliantly by Kornacki creeped higher and higher.  I do not remember when MSNBC projected Democrat Abigail Spanberger had defeated two-term Republican Dave Brat in Virginia’s 7th CD, but it was then I realized the anticipated “blue wave” (at least in the House) would materialize. When Democrat Max Rose beat two-term incumbent Republican Dan Donovan in New York’s 11th CD (on Republican-leaning Staten Island), it was off to the races.

Finally, at just before 11 pm EST, MSNBC (OK, I cannot find when they made their call, but it was likely within a few minutes of CNN) projected a Democratic takeover of the House.

A few minutes later, a not-yet-asleep Nell came downstairs to say that one of our politically-like-minded downstairs neighbors had texted her appreciation of my (partially-restrained) whooping-dancing “We got the House! We got the House!”

For the first time since the election of Republican Donald J. Trump as president of the United States, accompanied by a Republican House and Senate, plus a conservative-leaning Supreme Court, I truly exhaled.


In my previous post, I laid out a series of “projected” final margins for 17 (of 35) Senate races and all 36 governor’s races. In this post, I described two simple models of the number of House seats Democrats would net in 2018 based upon the change from 2016 in the Democratic (vs. Republican) margin in the total vote cast nationwide for the House. In 2016, Democrats lost the total national House vote by 1.1 points (while netting 6 seats as they improved by 4.7 points from 2014).

Votes are still being tabulated across the country, especially in California, but enough time has passed since Election Day to see how my projections compared to the actual margins (and to the FiveThirtyEight.com assessment of those same races), starting with the House.

House. According to the indispensable Cook Political Report vote tracker, as of 6 pm EST on November 18, 2018, nearly 110.7 million votes had been cast in House races. For perspective, 81.0 million, 86.8 million and 78.8 million House votes were cast in the last three midterm elections (2006, 2010, 2014), respectively. And that total was 129.8 million in the last presidential election year (2016). (House election data from the Cook tracker and here).

Democrats have thus far won 53.0% of those votes, compared to 45.7% for Republicans (and 1.3% for a smattering of third-party candidates) for a Democratic margin of 7.7 points…and an 8.8-point shift towards the Democrats from 2016 (and 13.5 points from 2014!)

According to my preferred “simple” model (change in margin only), a shift of 8.8 points would yield a gain of 26 seats (and give Democrats a 72% chance of regaining House control). My “complex” model (accounting also for whether the election was a midterm or not) was more bullish on the net seat gain (30) but more bearish on the probability (64%). Averaging across the two models yields a net of 28 seats and a 68% probability of Democratic House control.

Meanwhile, FiveThirtyEight.com’s final House forecasts projected a Democratic national House margin of 9.2 points (the median of their Lite, Classic and Deluxe forecasts) and a net gain of 38 (ditto) seats. Using the FiveThirtyEight.com projected House margin ups my average projected House seat gains to 33 with an 82% chance of regaining control.

With three-seven House races yet to be called, the likeliest outcome is that Democrats will net 38 (36-41) House seats, widely geographically dispersed: six (with Republican David Valadao the likely winner in CD 21) in California; four each in New Jersey and Pennsylvania (+5 D, +1 R); three each in New York and Virginia; two each in Florida, Illinois, Iowa, Michigan and Texas; and one each in Arizona, Colorado, Georgia (with incumbent Republican Rob Woodall leading Democrat Carolyn Bourdeaux by just 419 votes[1]), Kansas, Maine, New Mexico (almost certainly), South Carolina and Washington. Incumbent Republican Mia Love also leads Ben McAdams by just 419 votes. Minnesota showed no net change as Democrats flipped the 2nd and 3rd CDs while Republicans flipped the 1st and  8th CDs.

Based on the information I had on the morning of Election Day, that is 5 (3-8) seats more than I projected Democrats to net, well below the average nine seats by which my models “missed” across 24 previous midterm elections—and consistent with my models underestimating gains/losses in “wave” elections.

FiveThirtyEight.com almost perfectly nailed the actual Democratic net gain of seats, though (as of this writing) they overestimated the Democratic national House margin by 1.5 points; historically, this is not an especially large difference.

Most fascinating, however, is that a net gain of 38 House seats would actually be one seat higher than the upper range of what NBC was projecting at 9 pm EST on Election Day. Vote counting may be laborious and require infinite patience, but it is ultimately rewarding.

Senate. Table 1 compares the actual margin (Democratic percentage of total vote minus Republican percentage of total vote) in 33 2018 U.S. Senate races; italicized states indicate Republican pickups while boldfaced states indicate Democratic pickups. I excluded California, where incumbent Democrat Dianne Feinstein beat fellow Democrat Kevin de Leon by 9.0 points, and the special election in Mississippi, where incumbent Republican Cindy Hyde-Smith will face Democrat Mike Espy in a November 27 runoff. The latter race should be an easy win for Hyde-Smith in ruby red Mississippi (18.5 points more Republican than the nation as a whole, according to my 3W-RDM), but Hyde-Smith’s recent comments may make this race closer than expected.

Table 1. Comparing projected to actual 2018 U.S. Senate election margins*

State 3W-RDM Actual Difference

(Projected – Actual)

AV Difference

(Projected – Actual)

JBWM 538.com JBWM 538.com
Hawaii 34.3 42.2 -11.2 11.2
Vermont 27.7 39.9 -1.3 1.3
Maryland 22.6 33.9 -3.3 3.3
Massachusetts 22.1 24.8 -1.3 1.3
New York 21.6 33.0 4.8 4.8
Rhode Island 18.0 23.0 -5.6 5.6
Connecticut 12.8 20.2 -1.2 1.2
Delaware 12.5 22.2 -4.7 4.7
Washington 12.1 17.0 -5.4 5.4
New Jersey 12.0 10.6 1.5 -0.9 1.5 0.9
New Mexico 6.5 23.5 5.3 5.3
Maine 5.9 19.0 -0.9 0.9
Michigan 2.2 6.6 -6.3 -4.6 6.3 4.6
Nevada 2.0 5.0 4.7 4.0 4.7 4.0
Virginia 1.5 16.0 0.2 0.2
Minnesota SE 1.5 10.6 1.4 1.0 1.4 1.0
Minnesota 1.5 24.1 2.7 2.7
Wisconsin 0.7 10.8 -0.8 -2.0 0.8 2.0
Pennsylvania -0.4 12.8 -2.0 1.3 2.0 1.3
Florida -3.4 -0.2 -2.2 -3.4 2.2 3.4
Ohio -5.8 6.4 -5.7 -5.0 5.7 5.0
Arizona -9.7 2.2 0.7 0.5 0.7 0.5
Texas -15.3 -2.6 3.2 1.9 3.2 1.9
Missouri -15.9 -6.0 -5.5 -7.0 5.5 7.0
Indiana -16.3 -5.9 -7.1 -9.6 7.1 9.6
Mississippi -18.5 -20.3 0.8 0.8
Montana -18.6 3.5 -0.2 -1.2 0.2 1.2
Tennessee -25.8 -10.8 -6.3 -5.4 6.3 5.4
Nebraska -25.8 -19.6 -4.7 4.7
North Dakota -29.4 -10.8 -2.4 -6.0 2.4 6.0
Utah -33.1 -32.2 -2.8 2.8
West Virginia -35.5 3.3 0.0 -4.2 0.0 4.2
Wyoming -45.7 -37.0 7.1 7.1
Average Difference

(all projected elections)









Average Difference

(both projections only)









      *Excluding California (two Democrats) and the special election in Mississippi (runoff

      November 27, 2018)

States are sorted from most-to-least Democratic, according to their 3W-RDM score. The table presents the numeric and absolute value of the difference between the actual and projected Democratic margins in each election for both JustBearWithMe (JBWM) and FiveThirtyEight.com. Two sets of averages are presented at the bottom of the table: one was calculated using every election projected (I only projected the 17 most “interesting” races, while FiveThirtyEight.com projected all 35) and one was calculated only using the 16 listed Senate elections projected by both JBWM and FiveThirtyEight.com.

With Democratic Senator Bill Nelson conceding to Republican Rick Scott in the Florida Senate race, and the runoff in Mississippi still likely to result in a Republican hold, Democrats appear to have lost a net of 2 Senate seats. Besides Florida, Republicans ousted Democratic incumbents in Indiana, Missouri and North Dakota; they also won hard-fought races in Tennessee and Texas. Democrats, however, beat incumbent Republican Dean Heller in Nevada and won the open seat in Arizona vacated by Republican Jeff Flake.

My final back-of-the-envelope estimate was a loss of 0.9 Senate seats, while the median final FiveThirtyEight.com projection was a loss of 0.5 Senate seats; this is at most a 1.5 seat underestimate, depending on what happens in Mississippi, though I was slightly closer to the actual outcome. Both projections “called” the Florida and Indiana Senate races wrong—while FiveThirtyEight.com called the Missouri Senate race wrong as well.

Both JBWM and FiveThirtyEight.com overestimated Democratic margins in a swath of states stretching from North Dakota (average 4.2 points) south and east to Florida (2.8); states in which both projections overestimated the Democratic margin by at least four points were Ohio (5.4, on average), Michigan (5.5), Tennessee (5.9), Missouri (6.3) and Indiana (8.4). FiveThirtyEight.com also underestimated Republican margins in solidly Democratic Delaware, Hawaii, Rhode Island and Washington, as well as in solidly Republican Nebraska.

At the same time, both projections underestimated Democratic margins in Nevada (4.4) and, to a lesser extent, Texas (2.7); FiveThirtyEight.com also significantly underestimated Democratic margins in New Mexico, New York and Wyoming.

Overall, I overestimated Democratic Senate race margins by an average of 1.7 points (3.1 points in absolute terms) while FiveThirtyEight.com missed by an average of 1.9 points (3.7 in absolute terms). Only looking at the 16 Senate races we jointly assessed, FiveThirtyEight.com’s performance is slightly worse: overestimating Democratic margins by 2.5 points (though just 3.6 in absolute terms). This suggests FiveThirtyEight.com performed slightly better in Senate races in which the winner was clear well in advance.

Governor. Table 2 compares the current actual margin (Democratic percentage of total vote minus Republican percentage of total vote) in 35 2018 gubernatorial elections; italicized states indicate Republican pickups while boldfaced states indicate Democratic pickups. I excluded Nebraska because no polls were conducted of its gubernatorial election. States are again sorted from most-to-least Democratic.

Table 2. Comparing projected to actual 2018 U.S. Gubernatorial election margins**

State 3W-RDM Actual Difference

(Projected – Actual)

AV Difference

(Projected – Actual)

JBWM 538.com JBWM 538.com
Hawaii 34.3 29.0 -4.1 -1.1 4.1 1.1
Vermont 27.7 -15.0 -10.0 -3.6 10.0 3.6
California 23.2 22.6 5.7 5.2 5.7 5.2
Maryland 22.6 -12.7 -8.7 4.9 8.7 4.9
Massachusetts 22.1 -32.6 -2.7 1.4 2.7 1.4
New York 21.6 22.2 0.5 3.1 0.5 3.1
Rhode Island 18.0 15.5 0.1 -4.9 0.1 4.9
Illinois 14.7 15.4 -2.4 6.1 2.4 6.1
Connecticut 12.8 3.2 -3.9 -1.9 3.9 1.9
Oregon 8.7 6.4 -3.0 -0.1 3.0 0.1
New Mexico 6.5 14.4 5.2 5.0 5.2 5.0
Maine 5.9 7.6 -1.8 -4.7 1.8 4.7
Colorado 2.2 10.6 1.9 -1.8 1.9 1.8
Michigan 2.2 9.5 0.5 -0.2 0.5 0.2
Nevada 2.0 4.1 2.9 3.9 2.9 3.9
Minnesota 1.5 11.5 2.7 1.4 2.7 1.4
Wisconsin 0.7 1.2 -2.9 -0.5 2.9 0.5
New Hampshire 0.1 -7.0 -0.8 1.3 0.8 1.3
Pennsylvania -0.4 16.8 0.2 1.4 0.2 1.4
Florida -3.4 -0.4 -4.3 -4.6 4.3 4.6
Iowa -4.7 -2.7 -4.3 -3.5 4.3 3.5
Ohio -5.8 -4.2 -5.4 -5.7 5.4 5.7
Georgia -9.6 -1.4 -0.4 0.8 0.4 0.8
Arizona -9.7 -14.2 -2.5 -0.5 2.5 0.5
Texas -15.3 -13.3 2.6 3.6 2.6 3.6
South Carolina -15.7 -8.0 4.7 5.6 4.7 5.6
Alaska -19.2 -7.9 -5.1 -3.9 5.1 3.9
Kansas -23.4 4.5 7.1 5.8 7.1 5.8
Tennessee -25.8 -21.1 -5.7 -7.5 5.7 7.5
South Dakota -25.8 -3.4 -2.5 -0.9 2.5 0.9
Arkansas -28.2 -33.5 -3.5 -6.1 3.5 6.1
Alabama -28.4 -19.2 1.6 -3.0 1.6 3.0
Idaho -34.2 -21.6 -3.4 -5.2 3.4 5.2
Oklahoma -38.1 -12.1 -2.3 -4.9 2.3 4.9
Wyoming -45.7 -39.8 -4.2 -9.8 4.2 9.8
Average Projected-Actual -1.4 -0.7 3.4 3.5

      **Excluding Nebraska because no polls were conducted of its gubernatorial election

With Democrats Andrew Gillum in Florida and Stacey Abrams (sort of) in Georgia conceding to Republicans Ron DeSantis and Brian Kemp, respectively, Democrats netted six governor’s mansions. Democrats defeated Republican incumbents in Illinois and Wisconsin and won Republican-held open seats in Kansas, Maine, Michigan, Nevada and New Mexico; Republican Mike Dunleavey beat Democrat Mark Begich to win the open Independent-held governor’s mansion in Alaska. At the same time, Republicans cut their losses by narrowly holding the governor’s mansions in Florida, Georgia, Iowa and Ohio.

My final back-of-the-envelope estimate was a Democratic net gain of 9.2 governor’s mansions, while the median final FiveThirtyEight.com projection was 8.2 governor’s mansions. Both projections incorrectly “called” the gubernatorial elections in Florida, Iowa and Ohio for the Democratic candidate while mistakenly projecting a win in Kansas by Republican Kris Kobach over Democrat Laura Kelly.

Both JBWM and FiveThirtyEight.com overestimated Democratic margins by at least three points in Iowa (3.9 points on average), Idaho (4.3), Alaska (4.5), Florida (4.5), Arkansas (4.8), Ohio (5.5), Tennessee (6.6), Vermont (6.8) and Wyoming (7.0)—and, to a lesser extent Connecticut (2.9); all but Vermont[2] are at least 3.4 points more Republican than the nation as a whole. However, both projections underestimated Democratic margins in Nevada (3.4), New Mexico (5.1), South Carolina (5.2), California (5.5) and Kansas (6.5)—and to a lesser extent Texas (3.1); I addressed the woes besetting Kansas Republicans here.

Overall, I overestimated Democratic gubernatorial election margins by an average of 1.4 points (3.4 points in absolute terms) while FiveThirtyEight.com did so by an average of just 0.7 points (3.5 in absolute terms). Clearly, while both forecasts were identical in terms of correct and incorrect “calls,” FiveThirtyEight.com did a better job of assessing election probabilities and final margins.

Summary. Across all 51 Senate and gubernatorial elections “projected” by both JBWM and FiveThirtyEight.com, my projections overestimated Democratic margins by 1.5 percentage points on average, only slightly worse than the FiveThirtyEight.com average overestimation of 1.3 points. This is almost exactly the latter’s overestimation of the total national House Democratic margin by, at most, 1.5 points, suggesting that the 2018 midterm electorate was slightly more Republican than pollsters estimated (though well within historic parameters). The average miss in either direction of 3.4-3.5 points was also well within the range of recent elections.

However, these averages mask wide variation in Democratic under- and over-performance. In races with both a Senate and a gubernatorial election, Democrats had the most disappointing showings in Florida, Ohio and, especially, Tennessee; they also underperformed in Senate races in mostly Democratic states and in gubernatorial elections in mostly Republican states. Underperformance in two traditional presidential swing states—Florida and Ohio—could be of some concern to Democrats as they try to unseat President Trump in 2020.

On the brighter side, states where Democrats overperformed—California, Nevada, New Mexico and Texas—are all in the southwest (as is Arizona, where Democrats won a Senate race for the first time since 1988), an area of the country trending sharply Democratic. The closer-than-expected race for governor in South Carolina plus very close losses for governor in Florida and Georgia may also herald improved Democratic prospects in the southeast.

Besides geography, did state partisanship determine which state electorates were more or less Democratic than anticipated? For FiveThirtyEight.com’s gubernatorial election projections, the answer is…maybe. The Pearson correlation[3] between a state’s 3W-RDM and its numeric difference in gubernatorial margin is +0.44, while for the absolute value of the difference it is -0.37, suggesting that the more Democratic the state, the more Democrats overperformed in that state’s race for governor, while missing less in absolute terms. However, this could simply be an artifact of FiveThirtyEight.com’s newly-minted methodology for projecting gubernatorial elections.

The bottom line. As of January 3, 2019, Democrats will control the U.S. House of Representatives—most likely by 31 seats—for the first time in eight years, despite slightly “underperforming” in the total national House vote (which they still won by nearly 8 points). Their net gain of ~38 seats is the highest Democratic total since the Watergate elections of 1974 (49). Moreover, turnout in House elections—nearly 111 million votes and counting—will be at least 35.2% higher than the average turnout in 2006, 2010 and 2014. Democrats did not regain the Senate—suffering disappointing losses in Florida, Indiana and Missouri (as well as Tennessee and Texas)—but by winning elections in two southwestern states (Arizona, Nevada), they held their losses to two (or one, if they pull off an upset in Mississippi in 18 days), ground they will almost certainly make up in 2020, when the map is more favorable to Democrats (or, at least, far less unfavorable). Finally, they netted six governor’s mansions (including holding on to win a closer-than-expected race in Connecticut), despite disappointing losses in Florida, Georgia, Iowa and Ohio. Democrats will control governor’s mansions in 23 states—the most since the 2008 elections—which have a combined 280 electoral votes, meaning more than half of the nation’s population will have a Democratic governor.

Do not let a few disappointing results fool you. The Democratic wave in 2018 was strong and wide.

Until next time…

[1] We actually know Ms. Bourdeaux’s sister from our younger daughter’s former ballet class; following our move, we also share a dog park.

[2] Vermont voters may not have wanted to tell pollsters—in just three public polls—they were unwilling to vote for transgendered Democratic nominee Christine Hallquist.

[3] A number from -1.0 to +1.0 indicating the strength of the linear relationship between two variables. Briefly, a positive correlation means that as one variable increases the other variable does the same (and vice versa), while a negative correlation means that as one variable increases the other variable decreases (and vice versa). A correlation of zero means there is no association at all.

Published by

Matt Berger

I am a data geek, writer, investigator and film noir devotee with academic training in political science (Yale BA, Harvard MA), biostatistics (Boston University SPH MA) and epidemiology (Boston University SPH PhD). In January 2021, I finished writing Interrogating Memory: Film Noir Spurs a Deep Dive Into My Family History...and My Own for which I seek literary representation and a publisher. In Chapter 6: So...What Is Film Noir, Again?, I analyze my film noir database, which contains 4,825 titles. My musical holy trinity is Genesis, Miles Davis and Stan Ridgway. I am a liberal Democrat who understands a thriving democracy requires at least two mature political parties. I grew up just outside Philadelphia, and I live just outside Boston, where my wife and daughters keep me happy, sane and grounded. Please ask me anything else you want to know.

7 thoughts on “2018 Election Cheat Sheet: How did I do?

  1. […] 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. […]


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