2022 Elections Update: Stimulating simulations

On September 19, 2022, I published an updated set of projections for who will have the majority in the United States House of Representatives (“House”) following the 2022 elections, as well as who will win the 35 elections for the United States Senate (“Senate”) and 36 elections for governor. Since then, an additional 17 generic ballot polls – which I use to estimate the probability Democrats retain their House majority – have been released, along with 27 new Senate polls and 32 new governor’s race polls.

Having developed a “predictive margin of error” method to estimate the probability Democrats retain their House majority, I decided to use simulations to estimate the probability Democrats maintain their Senate majority, as well as whether Democrats net gain or lose governor’s mansions.

The logic is straightforward. Think of every probability the Democratic candidate wins a Senate (Table 1) or gubernatorial election (Table 2) as a box filled with 1,000 balls, each either blue or red; the number of blue balls is simply the probability the Democratic wins multiplied by 1,000. For example, as of September 25, 2022, the probability that Democrat Laura Kelly is reelected governor of Kansas is 58.5%. The box marked “Kansas governor” would thus have 585 blue balls and 415 red balls; in this example, red balls stand in for the probability either Republican state Attorney General Derek Schmidt or somebody else wins.

To simulate one possible election outcome, someone draws one ball from all 35 Senate boxes and one ball from all 36 governor’s boxes. Tally up the number of blue balls selected then replace them in the boxes. Add the number of blue Senate election balls to 36, the number of Democratic Senators not facing reelection in 2022. Add the number of blue gubernatorial election balls to six, the number of Democratic governors not facing reelection in 2022. Repeat some number of times.

For computational ease – this proved far trickier to do in Microsoft Excel (“Excel”) than I had expected, I assume every election is statistically independent. That is, I ignore two possible factors: one, that one party sweeps all or most of the close elections and two, that a Democratic win in one state increases the likelihood of a Democratic win in a “similar” state (i.e., if Democratic House member Tim Ryan wins the Ohio Senate election, Democratic Senate nominees Mandela Barnes of Wisconsin and John Fetterman of Pennsylvania – both Lieutenant Governors – are more likely to win their elections).

However, I could find no “draw ‘1’ with x probability” function in my version of Excel, so I jury-rigged this funtion using the random number generating function, or “=rand().” First, I generated 40,000 random numbers between 0.000 and 1.000. For each election, then, I used “=IF()” to generate “0” if the random number was less than the value 1.0001 minus the probability, and “1” otherwise. Unfortunately, this had the unintended effect of creating a very bimodal distribution of outcomes in which Democrats either lost all five of the closest Senate/gubernatorial elections or won all five.

Thus, I next generated a unique set of 40,000 random numbers for each election; this yielded a distribution of election outcomes far closer to normal. But whereas the first simulation method yielded a 66% chance Democrats retain Senate control, the second yielded a 97% chance. So, I decided to split the difference – run 40,000 simulations using each method then combine them into a single set of 80,000 simulations. See Figures 1 and 2 below for current distributions.


The House. As of September 25, 2022, I estimate Democrats lead Republicans on the generic ballot – how a respondent would choose between an unnamed Democrat and Republican if the election in their district were held today – by 0.1 pointz, 43.9% to 43.8%. Based upon this value, I estimate the probability Democrats retain a House majority is 26.6%. This is an increase of 3.9 points in one week. I also estimate Democrats will lose 10.5 seats, putting them at 211 or 212 (compared to the 222-213 majority they held following the 2020 elections), with a 95% confidence interval of -33.6 to +12.0.

Using only the 31 generic ballot polls conducted entirely after Labor Day, though, Democrats lead by 1.3 points, which equates to a 39.0% chance of retaining their House majority and an average loss of 6.7 seats (95% CI: -33.5 to +11.9). For Democrats to be nominal favorites to retain their House majority (p>50%), they need to win nationally by ≥2.3 points.

These probability and seat estimates are well in line with those from FiveThirtyEight.com, whose probabilities range from 30% (Deluxe) to 38% (Classic), with 211 seats assigned >50% probability of being won by the Democrat in the methodologically-conservative Deluxe model. However, if Democrats win every seat with probability>40%, they maintain a bare House majority across all three models.

Bottom line: A narrow House Republican majority is still more likely than not, though Democrats’ position steadily improves.


The Senate. As of September 25, 2022, 238 publicly-available Senate election polls have been conducted since November 1, 2021. These include four polls assessing a final matchup between two Republicans in Alaska: incumbent Senator Lisa Murkowski and former state official Kelly Tshibaka; Murkowski edges Tshibaka 51% to 49%. Only the Senate elections in California, Hawaii and Oregon – which incumbent Democrats Alex Padilla, Brian Schatz and Ron Wyden, respectively, are near-locks to win – and in Alabama, Idaho and North Dakota – which Republicans Katie Britt, Michael Crapo and John Hoeven, respectively, are near-locks to win – do not yet have publicly-available polling.

Table 1 shows updated projections for all 35 Senate elections.

Table 1: Democratic Senate win probabilities and projected final margins, 2022

StateFundamentalsPolling (WAPA)Poll WtFinal Projection
Democratic seatMarginP(D win)MarginP(D win) MarginP(D win)
New York25.8100.0%21.7100.0%0.8622.3100.0%
New Hampshire6.877.5%8.6100.0%0.858.396.7%
Estimated Democratic seats lost = 1.0 (range = 0.5 to 1.8)*
Republican seat       
North Carolina-5.734.1%-0.942.6%0.87-1.541.5%
South Carolina-19.14.8%-18.50.0%0.74-18.71.2%
South Dakota-32.80.2%-32.90.0%0.43-32.90.1%
North Dakota-38.60.0%n/an/an/an/a0.0%
Oklahoma (1)-41.00.0%-24.20.0%0.73-28.80.0%
Oklahoma (2)-41.00.0%-21.80.0%0.73-27.00.0%
Estimated Republican seats lost = 2.7 (range = 1.9 to 3.8)
Overall expected Democratic seats gained/lost = +1.7 (range = +0.1 to +3.3)

    *Adding or subtracting 3 points to all WAPA, including generic ballot estimates

Italics indicate open seats, while boldface indicates a likely “flip.” “Fundamentals” is the sum of state’s partisan lean (3W-RDM), current generic ballot estimate (-0.3) and incumbency advantage (Senate values: 5.5 points for Democrats, 3.3 points for Republicans); I assign one-third incumbency advantage to Democrats Mark Kelly of Arizona and Raphael Warnock of Georgia because they first won their seats in 2020 special elections. Essentially, this is what one would expect the Democratic margin to be for a generic Democratic vs. a generic Republican. The “fundamentals” probability the Democratic candidate wins is the likelihood of a Democratic margin of ≥0.0000001 given a normal distribution, with mean of +1.3 (mean historic “miss”) and standard deviation of 10.7.

Despite improvement on the generic ballot, “on paper,” Kelly and Warnock are modest underdogs, while Democratic incumbents in New Hampshire and Nevada are only modest favorites. On the flip side, the open Republican seat in Pennsylvania – vacated after two terms by Pat Toomey – is essentially a toss-up, albeit with the Republican candidate slightly favored. On average, I now give 21% weight to fundamentals and 79% weight to WAPA, an increase of WAPA weight of 2.0 points in one week.

Recall these categories:

Safe Republican (<5%)

Solid Republican (≥5 to <10%)

Likely Republican (≥10 to <20%)

Lean Republican (≥20 to <30%)

Tilt Republican (≥30 to <40%)

Toss-up (≥40 to ≤60%)

Tilt Democratic (>60 to ≤70%)

Lean Democratic (>70 to ≤80%)

Likely Democratic (>80 to ≤90%)

Solid Democratic (>90 to ≤95%)

Safe Democratic (>95%)

The difference between “Safe” and “Solid” is not always illuminating, so let us combine them here:

Safe/Solid Republican (n=13). Incumbents Crapo, Hoeven, John Kennedy (LA), Jim Lankford (OK), Jerry Moran (KS), Rand Paul (KY), Tim Scott (SC) and John Thune (SD) are near-locks to win. Republican nominees Britt, Markwayne Mullin and Eric Schmitt are also prohibitive favorites to win open seats in Alabama, Oklahoma and Missouri, respectively. Republican Senator Mike Lee is heavily favored – for now – to defeat Independent former CIA operative Evan McMullin (effectively the Democratic nominee) in Utah, while I project Murkowski has the edge over Tshibaka.

Likely Republican (n=4). Only one publicly-available poll has been conducted in the Senate races in Arkansas and Indiana, in which incumbent Republicans John Boozman and Todd Young, respectively, should be prohibitive favorites. Still, while MVM values of 5.0 and 3.4, respectively, introduce a modicum of uncertainty, Boozman and Young are both projected to win by double-digits.

Meanwhile, incumbents Chuck Grassley in Iowa and Marco Rubio in Florida face strong challenges from retired United States Navy Vice Admiral Michael Franken and House member Val Demings, respectively. Based solely on the fundamentals, Iowa is Likely Republican and Florida is Lean Republican, but polling puts Franken and Demings “only” 7.6 and 4.7 points behind, respectively – albeit Demings slightly closes the gap to 4.0 points using only the 14 polls conducted since August 1, 2022. Grassley, meanwhile, just turned 89 years old – meaning he could yet stumble due to age.

Lean Republican (n=0).

Tilt Republican (n=0).

Toss-ups (n=4). Here we find three Republican-held Senate seats which Democrats have made highly competitive. Two seats are those being vacated by Republicans Richard Burr of North Carolina (R+5.8) and Rob Portman of Ohio (R+9.8). On paper, these should be relatively easy holds for Republicans. In North Carolina, though, former State Supreme Court Chief Justice Cheri Beasley is within 0.9 points of House member Ted Budd – though she trails by 3.1 points in three polls conducted since Labor Day (average=B, according to FiveThirtyEight’s pollster ratings). That said, Budd is only averaging 45.0%, making this election extremely competitive; his percentage jumps to 48.1% in the three most recent polls. Meanwhile, in Ohio, Republican venture capitalist J.D. Vance trails Democratic House member Tim Ryan 44.9% to 44.6%. The strong caveat, however, is that only six polls rated at least B+ have thus far been conducted in this election, and they give Vance a lead of 2.3 points, though even then he still only averages 45.7%.

Luck may finally have run out, meanwhile, for two-term Wisconsin Republican Ron Johnson. While fundamentals cast this election as Tilt Republican, Johnson is only ahead of Barnes by 0.6 points in 10 polls. However, in the six such polls released since Labor Day (B+/A-), Barnes trails Johnson by 1.5 points, after having led by 3.5 points in polls averaging A-. Still, Johnson is not able to get much above 48%, even in the most recent polls.

And in Nevada, after leading by 2.8 points in 14 polls conducted through August 31, Democratic Senator Catherine Cortez Masto trails Republican former state Attorney General Adam Laxalt by 2.4 points in four polls (B+) conducted since Labor Day. Overall, I project Cortez Masto to win by a very narrow 0.7 points, down 1.7 points from last week.

The bad news for Democrats is that three of these races have moved toward Republicans over the last week, with only Ohio looking slightly better for Democrats. The good news for Democrats is that the Republicans are still only averaging 45.4% of the vote in states averaging R+4.6, meaning quite a few nominally Republican voters are hesitating.

Tilt Democratic (n=1). Warnock leads former National Football League player Herschel Walker in Georgia 47.2% to 45.6% overall, and 47.6% to 45.8% in nine publicly-available polls conducted since Labor Day (B average). Clearly, Warnock has improved his position since Labor Day. However, Georgia is still a Republican-leaning state (R+6.5) and a runoff occasioned by neither candidate winning a majority on Election Day remains a strong possibility. If the race goes to a January runoff, FiveThirtyEight.com projects Walker to win an average 68% of the time.

Lean Democratic (n=0).

Likely Democratic (n=1). The only reason Democratic Senator Mark Kelly is not a solid/safe choice to defeat venture capitalist Blake Masters is the Republican lean of Arizona (R+6.1). Kelly is already polling at 48.4%, however, and I project him to win by 4.8 points.

Solid Democratic (n=1). The Senate seat most likely to change partisan hands is that held by retiring Republican Pat Toomey in Pennsylvania. Democratic Lieutenant Governor John Fetterman, already averaging 49.3%, holds an 8.3-point lead over television celebrity Dr. Mehmet Oz. While Fetterman’s stroke has complicated this race, and Oz only trails by 4.6 points in three polls (B+/A-) conducted since Labor Day, Fetterman averages 49.9% in those polls, putting him on the doorstep of victory.

Safe Democratic (n=11): Incumbents Michael Bennet (CO), Richard Blumenthal (CT), Tammy Duckworth (IL), Maggie Hassan (NH), Patty Murray (WA), Padilla, Chuck Schumer (NY), Schatz, Chris Van Hollen (MD) and Wyden (OR) are near-locks to win reelection. Murray was effectively reelected on August 2, when she won 52.3% of the vote in an all-candidate primary; all Democrats combined won just under 55% of the vote. Meanwhile, House member Peter Welch is all-but-certain to win the Vermont Senate seat being vacated by seven-term Democrat Pat Leahy.

Bottom line: There is an 81.7% chance Democrats hold at least 50 Senate seats – and thus maintain the majority. In fact, there is a 66.8% chance Democrats net add Senate seats, with one (15.9%) and four (15.9%) being the most likely outcomes. Still, there is a 12.4% chance Democrat net lose one seat, giving Republicans a narrow 51-49 majority. Overall, there is an 84.7% chance the 2022 elections see Democrats ranging between a net loss of one and a net gain of four Senate seats, for an over/under of +1.5.

Figure 1: 2022 Senate election distribution


Governors. As of September 25, 2022, 266 publicly-available gubernatorial election polls have been conducted since November 1, 2021. Only those in the open seat in Hawaii – which Democrat Josh Green is a near-lock to win – and in Alabama, Idaho, Nebraska, South Dakota, Tennessee, and Wyoming – which Republicans Kay Ivey, Brad Little, Jim Pilllen, Kristi Noem, Bill Lee and Mark Gordon, respectively, are near-locks to win – do not yet have publicly-available polling.

A net gain of three governor’s mansions by Democrats would give them 25, giving them parity for the first time since 2010. Table 2 shows updated values for all 36 gubernatorial elections in 2022.

Table 2: Democratic gubernatorial win probabilities and projected final margins, 2022

StateFundamentalsPolling (WAPA)Poll WtFinal Projection
Democratic seatMarginP(D win)MarginP(D win) MarginP(D win)
New York20.386.0%13.1100.0%0.8314.397.6%
Rhode Island21.987.8%24.7100.0%0.7424.096.8%
New Mexico16.881.3%6.188.4%0.966.688.1%
Estimated Democratic seats lost = 2.1 (range = 1.4 to 3.0)*
Republican seat       
New Hampshire-12.624.9%-18.50.0%0.86-17.73.5%
South Carolina-29.75.6%-7.30.0%0.76-12.61.3%
Nebraska-25.09.0%    9.0%
Tennessee-41.01.4%    1.4%
Alabama-43.01.1%    1.1%
South Dakota-43.41.0%    1.0%
Idaho-48.60.5%    0.5%
Wyoming-61.30.1%    0.1%
Estimated Republican seats lost = 2.9 (range = 2.6 to 3.3)
Overall expected Democratic seats gained/lost = +0.9 (range = -0.4 to +1.9)

    *Adding or subtracting 3 points to all WAPA, including generic ballot estimates

The gubernatorial incumbency advantages are 10.4 points for Democrats and 13.9 points for Democrats. On average, I now give 17% weight to fundamentals and 83% weight to WAPA, an increase of WAPA weight of 1.0 points since last week.

Safe/Solid Republican (n=16). Incumbents Mike DeWine (OH), Mike Dunleavy (AK), Gordon, Ivey, Lee, Little, Henry McMaster (SC), Noem, Kim Reynolds (IA), Kevin Stitt (OK) and Chris Sununu (NH) are near-locks for reelection. University of Nebraska Board of Regents member Pillen and former White House spokesperson Sarah Huckabee Sanders will be the next Republican governors of Nebraska and Arkansas, respectively.

Meanwhile, Democrats Stacey Abrams (GA), Charlie Crist (FL) and Beto O’Rourke (TX) trail incumbent Republican governors Brian Kemp, Ron DeSantis and Greg Abbott, respectively, by an average 6.1 points. The lowest polling average among the three incumbents is Abbott’s 48.5%, though, making it difficult to see how any of these Democrats win.

Likely Republican (n=1). Popular Republican governor Phil Scott will win reelection, despite Vermont’s D+28.9 status.

Lean Republican (n=0).

Tilt Republican (n=0).

Toss-ups (n=3). Two governors who first won in the 2018 Democratic wave find themselves in a pitched battle for reelection: Kelly in Kansas and Steve Sisolak in Nevada. The good news for Kelly in heavily Republican Kansas (R+21.3) is that in two polls conducted at least in part after Labor Day, she leads Schmidt 46.9% to 42.6%, putting her much closer to victory; overall, in four polls, she leads 46.6% to 43.4%. Meanwhile, Sisolak’s lead over Clark County Sheriff Joe Lombardo has shrunk to 43.7% to 43.4% – and he trails 44.5% to 43.1% in three polls (A-/B+) conducted since Labor Day. Still, I project him to win by 1.9 points, and Kelly by 0.5 points, primarily on the strength of incumbency.

The open governor’s race in Arizona is a pure toss-up right now – with Democratic state Attorney General Katie Hobbs the barest 54.2% favorite to win in this R+6.1 state. despite a projected 0.15-point loss to television personality Kari Lake. This is the first of three states in which a Democrat is at least even money to replace a retiring Republican governor.

Tilt Democratic (n=5). The open governor’s race in strongly-Democratic Oregon (D+10.3) is in doubt because of Independent Betsy Johnson, a former Democratic state senator, and a lack of polling since mid-August – and only four polls overall (B-). Still, I project Democratic former State House Speaker Tina Kotek to edge Republican former State House Majority Leader Christine Drazan by mid-to-high single digits, especially with the tendency of third-party candidates to lose support closer to Election Day.

One incumbent Democratic governor who improved his position over the last week is Tony Evers in Wisconsin. While only averaging 47.6%, he is 2.2 points ahead of businessman Tim Michels, and I project him to win by 2.6 points.

Lean Democratic (n=0).

Likely Democratic (n=1). The only reason New Mexico Democratic Governor Michelle Lujan Grisham is not a solid/safe choice to defeat Republican former meteorologist Mark Ronchetti is that she is averaging 47.1% in seven very high-quality (A- average) publicly-available polls. I project Lujan Grisham to win by mid-to-high single digits.

Solid/Safe Democratic (n=13). Two states in which Democrats are near-locks to win back governor’s mansions are Maryland and Massachusetts, with former Army Captain Wes Moore and state Attorney General Maura Healey, respectively, projected to win by 20-25 points. Two other Democratic statewide officials are heavy favorites to win governor’s mansions held by retiring Democrats: Lieutenant Governor Green in Hawaii and Attorney General Josh Shapiro in Pennsylvania.

That leaves eight incumbent Democrats who are at least 9-1 favorites to win reelection: Kathy Hochul (NY), Ned Lamont (CT), Dan McKee (RI), Janet Mills (ME), Gavin Newsom (CA), Jared Polis (CO), J.B. Pritzker (IL), Tim Walz (MN) and Gretchen Whitmer (MI).

Bottom line: There is a 58.3% chance Democrats net at least one governor, with the most likely outcome by far (43.1%) being a net gain of three, bringing Democrats to parity for the first time since 2010. However, there is also a 27.7% chance Democrats net lose one or two governor’s mansions. Overall, there is a 77.0% chance the 2022 elections see Democrats ranging between a net loss of two and a net gain of three governor’s mansions, for an over/under of +0.5.

Figure 2: 2022 gubernatorial election distribution [Ed. Note: This is a corrected graph, with data as of 1:30 am EST September 28, 2022]


While Democrats find themselves in a good position right now – at least modest favorites to net Senate seats and governor’s mansions, while limiting losses in the House to ~10 seats – it would only take a not-historically-unusual polling miss of 3-4 points in Republicans’ favor to flip the script. In this scenario, Democrats still gain the Senate seat in Pennsylvania, while losing in Georgia and Nevada for a net loss of one seat and control of the Senate. Democrats would still win back governor’s mansions in Maryland and Massachusetts, while losing in Kansas, Nevada and Wisconsin, for a net loss of one governor’s mansion. And the likelihood of retaining House control would drop to 4.7%, centered around a loss of 22 seats.

This is what would happen if undecideds broke 2-1 Republican across the board, in line with midterm election history. However, it is equally plausible Democrats overperform polls by a similar amount. In this scenario, Democrats would be favored (66.5%) to retain House control, most likely gaining one or two seats. Not only would Democrats flip Pennsylvania, while holding all their Senate seats, they would also add North Carolina, Ohio and Wisconsin for a gain of four seats. They would still top out at netting three governor’s mansions.

As of late September, though, I prefer to drive straight down the middle, while awaiting new polling to see if Republican leads in key states since Labor Day hold.

Early voting has already begun in Minnesota, South Dakota, Vermont, Virginia and Wyoming, and is about to start in Illinois and Michigan.

Until next time, please register to vote, if you have not already done so! Then please vote! And if you like what you read on this website, please consider making a donation. Thank you.

2 thoughts on “2022 Elections Update: Stimulating simulations

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s