Simulated voters
4,597
Simulated voters · U.S. Senate · Maine 2026
Simulated voters · If Graham Platner exits
Maine Senate simulation compares nine potential Democrats against Susan Collins
Heather Cox Richardson led Susan Collins by 7 points and Shenna Bellows led by 5 among simulated Maine voters, both more than the method's typical error of 4.1 points. The other seven potential replacements for Graham Platner were within that error. The simulated voters were built from the records of 4,597 registered Maine voters in all 16 counties. We tested the method on five certified past Maine elections and adjusted the estimates using Collins–Platner public polling.
Counties covered
All 16
Margin of error
±4.1 pts
Validated against
5 certified races
The matchups
Every replacement against Collins
Finding
Heather Cox Richardson had the strongest estimate, Richardson +7. Valli Geiger had the weakest, Collins +2. Seven of the nine matchups fell within the method's typical error of 4.1 points.
Each matchup was simulated separately on the same voter panel to avoid question-order effects. Differences within about 4 points, the reported margin of error*, should be treated as ties.
| Democrat | Result vs. Collins | Read |
|---|---|---|
| Heather Cox RichardsonHistorian, Letters from an American | Richardson +7 | Beats Collins |
| Shenna BellowsMaine secretary of state | Bellows +5 | Beats Collins |
| Jared GoldenU.S. representative, ME‑02 | Golden +2 | Toss‑up |
| Troy JacksonFormer Maine Senate president | Jackson +2 | Toss‑up |
| Patrick DempseyActor, Maine native | Dempsey +1 | Toss‑up |
| Nirav ShahFormer Maine CDC director | Shah +1 | Toss‑up |
| Dan KlebanMaine Beer Company co‑founder | Collins +1 | Toss‑up |
| Jordan WoodFormer congressional chief of staff | Collins +2 | Toss‑up |
| Valli GeigerState representative, Rockland | Collins +2 | Toss‑up |
* The 4.1-point figure comes from past prediction errors. After applying the calibration correction, we compared estimates for five certified Maine elections with their results. The typical miss was about 4.1 points. We treat candidates within that range of each other as tied.
Where each candidate wins and loses
Democrats lead among unaffiliated voters and in the 1st District
The table breaks out estimated support by party affiliation, congressional district, and gender. Unaffiliated voters make up a third of Maine's electorate. All nine Democrats led among those voters and in the 1st District. Collins led in the 2nd District in every matchup.
| Democrat | Statewide | Unaffiliated | ME‑01 | ME‑02 | Men | Women |
|---|---|---|---|---|---|---|
| Heather Cox Richardson | D+7 | D+19 | D+13 | C+2 | C+4 | D+9 |
| Shenna Bellows | D+5 | D+16 | D+11 | C+3 | C+6 | D+8 |
| Jared Golden | D+2 | D+13 | D+6 | C+5 | C+4 | D+1 |
| Troy Jackson | D+2 | D+12 | D+7 | C+6 | C+8 | D+4 |
| Patrick Dempsey | D+1 | D+13 | D+6 | C+6 | C+7 | D+3 |
| Nirav Shah | D+1 | D+13 | D+6 | C+7 | C+9 | D+3 |
| Dan Kleban | C+1 | D+10 | D+4 | C+9 | C+10 | D+1 |
| Jordan Wood | C+2 | D+8 | D+3 | C+10 | C+11 | Even |
| Valli Geiger | C+2 | D+8 | D+3 | C+10 | C+12 | Even |
D = the Democrat ahead. C = Collins ahead. All figures use the same calibration adjustment as the statewide estimates.
Testing on past elections
Comparison with five certified Maine elections
Before estimating the 2026 matchups, we simulated five past Maine elections using the same voter panel. The method missed the margins by 2 to 8 points before the correction and identified the winner in all five. It also captured support for Collins among Democrats and independents who backed Democrats in other races.
| Certified race | Our estimate | Certified result |
|---|---|---|
| 2024 President (Harris / Trump) | Harris +5 | Harris +7 |
| 2020 President (Biden / Trump) | Biden +15 | Biden +9 |
| 2020 U.S. Senate (Collins / Gideon) | Collins +1 | Collins +9 |
| 2022 Governor (Mills / LePage) | Mills +20 | Mills +13 |
| 2018 Governor (Mills / Moody) | Mills +15 | Mills +8 |
These estimates are before the correction of about 4 points described under Calibration. After that correction, the typical miss on these five elections was about 4.1 points.
How it works
Voter profiles, questions, and calibration
Voter sample. We built simulated voters from the records of 4,597 registered Maine voters in the national voter file, covering all 16 counties. We weighted them to match the electorate's party and demographic composition in each county.
Simulated responses. The model rated each profile's likelihood of supporting the Democrat on a 0-to-10 scale. We ran each matchup separately to avoid question-order effects.
Profile information. The model received age, gender, race or ethnicity, and party registration. It received no names, addresses, or phone numbers. County and district were used to balance the sample and report results.
Calibration. Available public polling put Collins and Platner about even, while our simulation put Platner ahead by about 4 points. We subtracted about 4 points from each Democrat's estimate to match that benchmark. A separate correction estimated from past elections was similar.
Candidate familiarity. The model received a short description of each candidate and treated all nine as established figures. Lesser-known candidates might begin a 100-day campaign with less support than these estimates suggest. Their figures assume party support and sufficient voter familiarity.
Run it on your race
Use synthetic polling to compare candidates
The method called 9 of 10 winners in the 2026 New York and Maryland primaries before voting began. Civly uses it to estimate candidate support and test messages from registered-voter profiles.
Run date July 8, 2026 · simulated panel of 4,597 registered Maine voters drawn from the national voter file, all 16 counties · margin of error about 4.1 points, measured from the method’s misses on five certified past Maine elections after the calibration adjustment · all figures use a calibration adjustment based on Collins–Platner public polling available at the time · prepared by Civly.