Maine · U.S. Senate
Open this race on The Map ↗Troy Jackson has a 54.7% chance of winning after ranked-choice transfers. No final-round margin is published.
high / low: vote share (%) in the middle 80 in 100 simulations · shares are first-choice votes; winning chances include ranked-choice transfers, not a published final-round margin
About this field
Graham Platner withdrew July 10. Maine Democrats' 601-delegate convention confirmed Troy Jackson as the replacement nominee on July 25, with 566 of 571 ballots cast. Platner-era head-to-head polls are hypothetical matchups now and carry zero weight in the model (disclosed on the methodology page). Collins has always outrun her polling in a blue state.
Forecast share averages the simulated vote. Win chance counts how often a candidate wins. A wider range of outcomes can give a candidate a higher win chance despite a lower average share.
Forecast history
Latest reading · Sep 13 · first published Sep 9 · 80% range · margin points R+6.7 to D+9.1. Methodology
Hover the line, tap it, or use the arrow keys to inspect its history.
About this series
This comparable series begins on September 9, 2026, when the model version changed to CTMM 2.2. Earlier readings remain in the archive and are not joined as voter movement; faded points before September 9, 2026 are reconstructions, not forecasts issued on those days.
Faded: CTMM 2.2 reconstructed history: computed after the fact with each date's available polls and environment, without expert ratings; not an issued forecast. Issued forecasts begin at the launch marker.
The polls
Ledger weighted average D+2.4Used by the forecast: 11 polls (60-day half-life) · measured D+3.5 · after the fitted poll-error shift D+1.911 recorded polls · 11 eligible for the aggregate · 11 with positive weight
| Fieldwork | Added | Pollster | Result | Sample |
|---|---|---|---|---|
| from 2026-09-08 | 1h ago | Rasmussen Reports (R) ↗ | D+1.0D 46% · R 45% | 1,033 LV |
| from 2026-09-02 | 3d ago | YouGov ↗ | D+4.0D 48% · R 44% | 1,335 LV |
| from 2026-08-31 | 3d ago | SSRS ↗ | D+3.0D 48% · R 45% | 880 LV |
| from 2026-08-31 | 3d ago | CNN/SSRS ↗ | D+3.0D 48% · R 45% | 880 LV |
| from 2026-08-26 | Abacus Data ↗ | D+8.0D 50% · R 42% | 327 LV | |
| from 2026-08-06 | Beacon Research/Shaw & Company Research ↗Fox News | D+2.0D 48% · R 46% | 1,000 RV | |
| from 2026-07-27 | Hart Research Associates ↗Senate Majority PAC | D+4.0D 49% · R 45% | 802 LV | |
| from 2026-07-15 | University of New Hampshire ↗ | D+3.0D 49% · R 46% | 1,178 LV |
Explore poll adjustments
Ledger weighted average D+2.4
- Published result
- D+1.0
- Model read
- D+2.0
- Model weight
- 0.776
- Fieldwork
- 8 Sep–10 Sep
- Sample
- 1,033 LV
- Sponsor
- Republican sponsor · organization not listed
- Pollster quality
- 0.653
- Admission
- Included in the model
Recorded corrections: sponsor +1.73 points; pollster +1.45 points.
Wikipedia polling archive · first recorded by Call the Map 13 SepOpen poll source- Published result
- D+4.0
- Model read
- D+2.8
- Model weight
- 0.820
- Fieldwork
- 2 Sep–8 Sep
- Sample
- 1,335 LV
- Sponsor
- Not listed
- Pollster quality
- 0.648
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster −1.01 points.
The New York Times polling archive · first recorded by Call the Map 10 SepOpen poll source- Published result
- D+3.0
- Model read
- D+2.8
- Model weight
- 0.529
- Fieldwork
- 31 Aug–6 Sep
- Sample
- 880 LV
- Sponsor
- Not listed
- Pollster quality
- 0.550
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster 0.00 points.
The New York Times polling archive · first recorded by Call the Map 10 SepOpen poll source- Published result
- D+3.0
- Model read
- EVEN
- Model weight
- 0.534
- Fieldwork
- 31 Aug–6 Sep
- Sample
- 880 LV
- Sponsor
- Not listed
- Pollster quality
- 0.556
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster −3.12 points.
Wikipedia polling archive · first recorded by Call the Map 10 SepOpen poll source- Published result
- D+8.0
- Model read
- D+7.8
- Model weight
- 0.239
- Fieldwork
- 26 Aug–28 Aug
- Sample
- 327 LV
- Sponsor
- Not listed
- Pollster quality
- 0.550
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster 0.00 points.
The New York Times polling archive · first recorded by Call the Map 1 SepOpen poll source- Published result
- D+2.0
- Model read
- EVEN
- Model weight
- 0.279
- Fieldwork
- 6 Aug–10 Aug
- Sample
- 1,000 RV
- Sponsor
- Fox News
- Pollster quality
- 0.664
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster −1.48 points.
The New York Times polling archive · first recorded by Call the Map 23 AugOpen poll source- Published result
- D+4.0
- Model read
- D+1.0
- Model weight
- 0.154
- Fieldwork
- 27 Jul–1 Aug
- Sample
- 802 LV
- Sponsor
- Senate Majority PAC
- Pollster quality
- 0.550
- Admission
- Included in the model
Recorded corrections: sponsor −2.98 points; pollster 0.00 points.
The New York Times polling archive · first recorded by Call the Map 23 AugOpen poll source- Published result
- D+3.0
- Model read
- D+0.5
- Model weight
- 0.111
- Fieldwork
- 15 Jul–20 Jul
- Sample
- 1,178 LV
- Sponsor
- Not listed
- Pollster quality
- 0.488
- Admission
- Included in the model
Recorded corrections: sponsor −0.16 points; pollster −2.31 points.
The New York Times polling archive · first recorded by Call the Map 23 AugOpen poll sourceHow the margin was built
Follow each contribution to the margin. Wider ribbons mean more percentage points. Tap an input for its calculation and source.
The signed totals combine at the forecast. Displayed values are rounded. This is the model coordinate before ranked-choice transfers.
Winning chances include ranked-choice transfers. No final-round margin is published.
All calculations & sources
How this state voted, 2024 +6.940 points
The state's two-party presidential margin in 2024, from our own county sums — the same measurement the model's statewide terrain center is built from. Every pull below is measured from here, not from EVEN, which is why a landslide seat's listed pulls are small numbers and still land where the forecast does.
- 2024 presidential result for this state, two-party, from Call the Map's own county sums.
- Same source as Act I's 2024-president reference mark, so the origin lands on it.
This race’s polls +3.591 points
What this race’s own recent polling adds beyond its prior, after each poll is weighted for recency, sample size and pollster quality.
- 11 matchup-validated, sample/recency/grade-weighted poll(s), latest 2026-09-10
- YouGov (2026-09-08, n=1,335): D+4.0 · weight 1.35
- SSRS (2026-09-06, n=880): D+3.0 · weight 1.03
- CNN/SSRS (2026-09-06, n=880): D+3.0 · weight 1.03
- Abacus Data (2026-08-28, n=327): D+8.0 · weight 0.47
- Beacon Research/Shaw & Company Research (2026-08-10, n=1,000): D+2.0 · weight 0.45
- Hart Research Associates (2026-08-01, n=802): D+4.0 · weight 0.30
- … and 4 more below.
- Adjusted poll-bank aggregate D+2.5 · 10 recorded polls · 10 eligible for the aggregate · 10 with positive weight. The sealed model records a net polling contribution of +3.6 D. Observation weights are not the final model blend weight. Eligible polls: latest poll: 2026-09-08 (5 days old).
- Adjusted poll-bank aggregate D+2.5 · 10 recorded polls · 10 eligible for the aggregate · 10 with positive weight; recorded polling contribution +3.6 D. These observation weights must not be read as the model’s final prior-versus-polling weight. Eligible polls: latest poll: 2026-09-08 (5 days old).
National environment +1.988 points
The contribution to this race’s margin, not the national polling margin itself. The race’s loading, reference level and polling blend determine how much of the national climate reaches its final forecast.
- Three-source blend, updated 2026-09-08: 52% generic-ballot aggregates (D+6.5) · 28% special-election overperformance (D+9.0 across 46 specials) · 20% approval-implied (D+8.6 from net approval -21.7).
- Latest polls — generic ballot 2026-09-08 (5 days old), approval 2026-09-10 (3 days old).
- Generic-ballot average D+6.5 · support factor 0.84 (the share of that channel's capacity the admitted polls carry) — separate inputs; their product is a capacity diagnostic, not a margin.
- Weights are the 55/25/20 capacities scaled by each channel's evidence and renormalized, so thin polling widens the interval instead of pulling the center toward zero — 16% of the weight is carried that way.
- Blended national environment: D+7.6.
- Applied at full strength to this chamber's races.
- The work: national environment × 1 chamber strength = +2.0 D of this margin.
- Blended national environment: D+7.6 (updated 2026-09-08).
- Effective poll weight 84%; fundamentals share 16%, carried by the interval (×1.08) rather than by the center.
- The support factor is the share of the generic-ballot capacity the admitted polls carry; average × support is a capacity diagnostic, not a margin, and is not what the row above multiplies.
- Applied at full strength to this chamber: +2.0 of this margin.
Structural safeguards +0.024 points
Bounded corrections that keep the model consistent with structural facts.
- Applied only when a safe state's dynamic fundamentals point in the same direction as its strong presidential lean but are materially compressed toward zero.
- The 25% correction toward that lean improved safe-race MAE in strict expanding-window validation without changing a historical call.
- The disclosed adjustment is +0.0 D.
Fitted model, above the terrain shown −11.352 points
What the fitted model adds on top of the starting terrain above — incumbency, past results, campaign finance and the other fitted terms — measured from that terrain rather than from EVEN. It is a comparison with the starting point already shown, not a separate input. The source detail lists the variables the fit uses.
- Fitted baseline -4.412 minus starting point 6.940 = -11.352 points.
- For orientation, the presidential results here: 2024 D+6.9, 2020 D+8.7.
- The work: the −4.4 D fundamentals push is the sum of the dynamic formula's surviving variables for this race — each one's own contribution is listed below.
- fundamentals core = 25-term dynamic formula (mass fit over the master feature matrix, held-out-cycle validated; see matrix/feature_dictionary.md + mass_fit_report.json)
- 9-term formula, held-out validated.
These are the fitted model’s named contributions to the partisan coordinate, before the candidate-field calculation.
| Named factor | Contribution |
|---|---|
| FundamentalsThe admitted fitted baseline. Its surviving variables differ by office; the source detail above identifies those used for this race. | −4.41 |
| This race's pollsAdmitted head-to-head polls of this race, recency- and quality-weighted. | +3.59 |
| National environmentThe national environment’s contribution to the prior. Polling can attenuate its influence; this value is not the national polling margin. | +1.99 |
| Structural terrain safeguardA bounded pull toward presidential terrain in heavily partisan states. | +0.02 |
| Other factors | +0.00 |
Recent elections
| Election | Result | Votes cast |
|---|---|---|
| 2020 · U.S. Senate ↗ | R+9.2 | 828,305 |
| 2014 · U.S. Senate ↗ | R+37.0 | 616,996 |
| 2008 · U.S. Senate ↗ | R+22.8 | 724,430 |
| 2002 · U.S. Senate ↗ | R+16.9 | 504,899 |
Margins compare Democratic and Republican vote totals. Nonstandard ballots are labeled separately.
The money
Troy Jackson
DNo filingrecorded
— cash on handFiling date unavailable
Susan Collins ↗
R$16.2Mraised
$11.0M cash on handFiling through 06/30/2026
Bar length compares reported receipts in this race; the tick marks cash on hand. A missing filing stays blank rather than becoming $0.
One more fundraising reportCall the Map · $0
The candidates are comfortably out-fundraising the website covering them. A little rude, perhaps, but statistically unsurprising.
- Received so far
- $0
- Measured compute
- $26,188.58
Ko-fi and Buy Me a Coffee receipts are counted through Sep 1, 2026. Measured compute prices model runs at standard published API rates; it is not what I paid. Hosting, data and subscriptions, the domain and my own time are not counted. Donations buy gratitude, never a forecast adjustment.
Outside spending
Support + opposition · separate from receiptsFor and against Troy Jackson$18.2M
7 spending groups
| Group | For | Against |
|---|---|---|
| PINE TREE RESULTS PAC | $0 | $9.3M |
| SLF PAC | $0 | $3.5M |
| WinSenate | $2.8M | $0 |
| Government That Works PAC | $1.6M | $0 |
| Lead Maine Committee, Inc. | $0 | $355K |
| America PAC | $0 | $320K |
| CFFE PAC | $293K | $0 |
For and against Susan Collins$6.9M
16 spending groups
| Group | For | Against |
|---|---|---|
| WinSenate | $0 | $2.2M |
| Lead Maine Committee, Inc. | $955K | $0 |
| Planned Parenthood Votes | $0 | $755K |
| America's Credit Unions | $705K | $0 |
| STRONGER MAINE | $637K | $0 |
| Senate Leadership Fund | $435K | $0 |
| Government That Works PAC | $0 | $351K |
| CLEARPATH ACTION FUND, INC. | $241K | $0 |
| America PAC | $230K | $0 |
| Reproductive Freedom For All Freedom Fund | $0 | $170K |
| AFSCME WORKING FAMILIES FUND | $0 | $91K |
| LEAGUE OF LABOR VOTERS | $0 | $50K |
| NRRC | $0 | $36K |
| THE CONSERVATIVE CAUCUS DBA AMERICANS FOR CONSTITUTIONAL LIBERTY | $32K | $0 |
| RED SENATE | $13K | $0 |
| The Sentinel Action Fund | $1K | $0 |
Includes primary spending. Opposition is recorded against its named target; no benefit to another candidate is assumed.
$11.4M in outside spending on earlier candidates.
FEC filings · through 06/30/2026 · Definitions & method
Race context
- Forecast votes cast
- 658,212
- Forecast turnout
- 57.7% of the voting-eligible population
- 2024 presidential margin
- D+7.1
Statewide, 58.4% of the voting-eligible population is projected to cast a ballot; the lower figure above is the share projected to vote in this race.
Population profile Select a measure for its source and denominator
U.S. Census Bureau, 2022 American Community Survey 5-year estimates ↗
Coverage
5 stories · 4 quotes
- If Trump succeeds in restricting mail voting in the 2026 midterms, which he is attempting through a contentious executive order, it could help Republicans win key House and Senate seats as each party seeks a narrow path to a majority in either chamber. mainemorningstar.com/2026/09/11/r... ↗
Maine Morning Star · Official · 1d ago
curated state newsroom · recent Bluesky post · named-race match - Aren’t Ds favored to win both? Quinnipiac gives Dems +11 in generic congressional polling. In recent Senate polling, Roy Cooper is up double digits in North Carolina, Troy Jackson is up by 4 in Maine, and James Talarico in Texas, Sherrod Brown in Ohio and Mary Peltola in Alaska hold leads. ↗
Jen Rubin · Commentary · 2d ago
curated political commentary · recent Bluesky post · named-race match · election-topic match - "Collins is arguing that her presence in the Senate protects her constituents from a regime that she supports 95% of the time. When Mainers head to the polls, they are largely voting on whether her seniority and the privileges it affords the state is worth the cost to the rest of the nation." ↗
Maine Morning Star · Official · 3d ago
curated state newsroom · recent Bluesky post · named-race match · election-topic match - Sens. Susan Collins of Maine and Dan Sullivan of Alaska, both locked in tough reelection bids, reportedly declined to attend. mainemorningstar.com/2026/09/10/r... ↗
Maine Morning Star · Official · 3d ago
curated state newsroom · recent Bluesky post · named-race match - Women who remember life before Roe are turning away from Susan Collins ↗
Daily Kos Elections · Sep 8
- Brooks and Capehart on Trump calling Iran war 'small potatoes' ↗
PBS NewsHour Politics · Sep 4
- Susan Collins praises Elon Musk. What could go wrong? ↗
Daily Kos Elections · Sep 4
- Abortion rights group endorses Democrat Troy Jackson in critical Maine Senate race ↗
The Guardian US politics · Aug 26