Who will win the 2026 Maine Senate election? — Susan Collins

- [2026-10-01] DDHQ's model (updated 2:21 PM Oct 1) Decision Desk HQ's forecast for this race blends 43% fundamentals, 32% polls, and 25% markets , and as of the fetch shows the race at effectively 50%-50% between Collins and Jackson, with polling average Jackson 48.6% vs. Collins 47.2% (Jackson +1.4), Generic Ballot D+7.9, Projected Margin R+1 (https://votes.decisiondeskhq.com/races/2026-11-03/maine-us-senate-general-election). - [2026-09-30] A co/efficient (R) poll found A new co/efficient (R) poll in Maine finds Susan Collins (R) leading Troy Jackson (D) in the U.S. Senate race, 48% to 46% (https://politicalwire.com/2026/09/30/susan-collins-slightly-ahead-in-maine-senate-race/). - [2026-09-26] InsiderAdvantage poll: A new Insider Advantage poll in Maine finds Troy Jackson (D) is tied with Susan Collins (R) in the U.S. Senate race, 46% to 46% (https://politicalwire.com/2026/09/26/maine-senate-race-is-tied/). - [2026-09-24] NYT/Portland Press Herald/Siena poll (fielded Sept. 15-22): Collins led her Democratic challenger, former Maine Senate President Troy Jackson, by three points, 49% to 46% , with a margin of error of +/- 4.9 percentage points (https://www.pressherald.com/2026/09/24/maine-senate-election-poll-susan-collins-swing-voters/). - [2026-09-25] University of New Hampshire poll (Sept. 17-21): found the race effectively tied, with little movement from July, when Jackson led Collins 49% to 46% (https://www.wabi.tv/2026/09/25/jackson-holds-narrow-lead-over-collins-new-maine-senate-poll-top-races-tighten/). - [2026-09-30] AARP/Fabrizio Ward-Impact Research poll (Sept. 20-22): The former state Senate president is leading against Collins 50 to 47 percent, with 3 percent undecided , though voters 50-plus favor the five-term Republican over the Democratic candidate 53 to 44 percent (https://www.aarp.org/government-elections/maine-election-poll-2026/). - [2026-09-22] ProPublica published an investigation alleging a defense contractor donated $150,000 to a Collins super PAC through a shell company to get around campaign finance laws, and two months later, company executives were told they would get a $32 million contract , tied to convicted ex-Navatek CEO Martin Kao (https://spectrumlocalnews.com/me/maine/politics/2026/09/22/democrats-pounce-on-report-tying-collins-to-defense-contractor). - [2026-09-23] Collins' campaign manager Steve Abbott publicly rebutted the story, calling it "false and they are allegations from a guy who was awaiting sentencing for a significant federal offense who was trying to get his sentence reduced" (https://spectrumlocalnews.com/me/maine/politics/2026/09/23/collins--team-rebuts-propublica-story--calling-pay-for-play-allegations--false-). - [2026-09-30] Newsweek noted an FBI spokesperson told ProPublica the investigation had concluded years prior and "ultimately found nothing implicating Senator Collins" , giving Collins a partial rebuttal point even as the story continued to generate coverage (https://newsweek.com/susan-collins-takes-another-poll-lead-amid-questions-over-fbi-investigation-12511674). - [2026-09-28] A Portland Press Herald editorial board op-ed criticized Collins' response to the story, and Collins's attacks on ProPublica to undermine the story prompted it to issue a follow-up report calling her claims "incorrect and misleading" (https://heathercoxrichardson.substack.com/p/september-28-2026). - [2026-09-17] DDHQ analysis described the contest as the closest test of Collins's career, noting Jackson finds himself just narrowly ahead of Collins in Decision Desk HQ's Maine polling average, about 47%-45% , while both candidates currently have about a 1 in 2 shot of winning in Decision Desk HQ's Maine Senate forecast (https://decisiondeskhq.substack.com/p/susan-collins-troy-jackson-maine-senate-polls-2026-midterms). - [2026-07-10 to 2026-07-25] Background: Graham Platner won the Democratic primary but withdrew from the race on July 10 following sexual assault accusations and other controversies , and Jackson was chosen to replace Platner via a nominating convention held on July 25 (https://en.wikipedia.org/wiki/2026_United_States_Senate_election_in_Maine). - [2026-06/2026] Campaign finance: as of DDHQ's latest filing data (July quarterly, period ending 6/30/2026), Collins raised $18,930,078 and spent $9,187,155, while Platner (pre-withdrawal) had raised $21,050,419 and spent $19,287,361 — the current financial snapshot for Jackson post-switch was not separately broken out (https://votes.decisiondeskhq.com/races/2026-11-03/maine-us-senate-general-election). BOTTOM LINE: The race remains a true toss-up heading into October, with recent polls split almost evenly (some showing Collins up 2-3, others showing Jackson up 2-4, all within margin of error), and DDHQ's blended forecast as of Oct 1 pegging Collins at exactly 50% probability. A late-September ProPublica corruption story has added uncertainty but has not produced a clear, decisive shift in the polling trend either way through month's end. NOT FOUND: No confirmed post-October-1 polling or any media consensus "race call"; no evidence the general election (Nov. 3, 2026) has occurred or been decided; could not find a detailed breakdown of Jackson's current fundraising totals post-primary switch.

- [2026-09-30] Reference class: Cook Political Report currently rates the race a **Toss Up**, having moved from "Lean R" after Gov. Janet Mills entered the Democratic primary in Oct 2025; Democrats believe Jackson is generic enough to take advantage of Collins' unpopularity while Republicans think independents will again back the universally-known Collins https://www.cookpolitical.com/senate/race/488601 - [2026-09-29] Sabato's Crystal Ball and Inside Elections also rate Maine a toss-up, placing it among the handful of genuinely competitive Senate seats this cycle, per The Cook Political Report and Sabato's Crystal Ball rate the race as a toss-up https://www.newsweek.com/susan-collins-troy-jackson-maine-senate-race-poll-12482806 - [Historical base rate] Collins has won five consecutive Senate elections since 1996 (2002, 2008, 2014, 2020), including twice during Republican wave elections (2002, 2014) and in three presidential-year cycles that elected Democratic presidents nationally and in Maine (1996, 2008, 2020) , giving her a 100% historical win rate in this seat over 30 years. - [2020 precedent, most comparable race] In her last reelection, Collins was down in the polls and seemingly on track to lose the seat she'd held for 24 years—then she won by nine points , with not a single public poll showing her winning for months before the election https://19thnews.org/2020/12/susan-collins-senate-race-2020-defied-the-odds/ - [Polling trendline 2026] Multiple fall 2026 surveys show a true toss-up with movement toward Collins late: a Sept 15-22 NYT/Siena poll had the five-term incumbent ahead of Jackson for the first time, 49% to 46%, within the margin of error , while earlier CNN/SSRS (Aug31-Sep6) and Fox polls had shown Jackson leading https://www.pressherald.com/2026/09/24/susan-collins-polling-maine-senate-race/ - [2026-09-30] A late co/efficient poll found Collins leading Jackson 48% to 46% , continuing a modest late shift toward the incumbent https://politicalwire.com/2026/09/30/susan-collins-slightly-ahead-in-maine-senate-race/ - [2026-09-28] RealClearPolitics' polling average as of late September had Jackson at 47.4% and Collins at 46.4%, a 1-point difference , essentially a statistical dead heat https://www.yahoo.com/news/politics/articles/poll-shows-susan-collins-deadlocked-235212830.html - [Betting markets as outside-view input] Polymarket's "Maine Senate Election Winner" market (sibling market, resolves Nov 3, 2026) showed, as of Oct 1, 2026, Troy Jackson at 59% versus Susan Collins at 41%, with the race described as remaining a statistical toss-up despite the lean toward Jackson https://polymarket.com/event/maine-senate-election-winner - [Market volatility] Prediction-market odds swung sharply on news: Jackson's Polymarket odds rose to 74% (from 70%) and his Kalshi odds to 72% (from 67%) after a ProPublica report on an abandoned FBI probe tied to Collins , before reportedly reversing somewhat after subsequent pro-Collins polling https://www.newsweek.com/collins-fbi-probe-gives-boost-jackson-maine-senate-race-12476800 - [Candidate/structural factor] Collins was unopposed for the GOP nomination while Democrats' original nominee Graham Platner won the primary but withdrew July 10 amid controversy, with Jackson chosen as replacement via a July 25 nominating convention , giving Jackson a shorter runway and lower name recognition than a typical challenger https://en.wikipedia.org/wiki/2026_United_States_Senate_election_in_Maine - [Partisan lean caveat] Despite Collins' personal track record, Democrats have not won a Senate election in Maine since 1988 , underscoring that the seat itself is historically Republican-held even as the state votes Democratic for president, which favors Collins' personal brand holding over a generic-R. BOTTOM LINE: The strongest base-rate signal is Collins' unbroken 30-year string of Senate wins in Maine (5-for-5, including as a come-from-behind underdog in 2020), which argues for giving her meaningfully better odds than either current polling (~toss-up/dead heat) or prediction markets (Jackson ~59-70%, Collins ~31-41% on Polymarket as of early Oct) suggest; historically, markets and polls have underestimated Collins late in the cycle. NOT FOUND: A specific 538-style statistical win-probability model (e.g., Silver Bulletin, The Economist) for this race; official PredictIt pricing; any post-Oct-1 polling or market movement.

YES means: Susan Collins (R) is declared the winner of the 2026 Maine U.S. Senate election (ranked-choice voting, Nov. 3, 2026 election day), either by a media-consensus race call or by certified results, before the market's July 7, 2027 close. - [2026-10-01] AARP/Fabrizio Ward-Impact Research poll (Sept. 20-22, n=982) shows Jackson leading 50-47 overall, but Collins, who trailed in every public poll in 2020 before winning by 8 points, has more swing-voter support than any Republican in AARP's seven battleground Senate polls , with Collins winning 11% of Democrats, the most for any Republican in the series, and running 7 points ahead of her party on the generic ballot — a direct mechanism for the classic late Collins crossover surge. - [2026-10-01] Same AARP poll: Collins was the only candidate in the series with a positive image among swing voters, at 59% favorable to 32% unfavorable, while Jackson was underwater at 23% to 60%, the worst of any major-party Senate candidate AARP tested . - [2026-09-24] NYT/Siena crosstabs: one of Collins' largest advantages comes from white voters without college degrees, leading Jackson 62% to 32% among those voters , and 59% of respondents said Collins would be better at bringing money and resources back to the state, compared with 35% who chose Jackson , reinforcing Collins' incumbency/Appropriations-chair advantage as a persuasion lever. - [2026-09-24] Same poll found approximately twelve percent of voters who backed Kamala Harris in 2024 said they now planned to support Collins , direct evidence of the cross-partisan coalition Collins needs to repeat her 2020 comeback. - [2026-09-14] Collins secured a high-profile centrist endorsement: Joe Manchin, a former longtime Democratic U.S. senator and centrist known for breaking with his own party, endorsed Republican Sen. Susan Collins' reelection campaign , reinforcing her "independent voice" brand with swing/moderate voters. - [2026-09-27 (financials through 6/30)] FEC filings confirm Collins' financial edge: she has $18.93M raised, $7.7M spent (through June 30) with $11M cash-on-hand entering Q3, while the Senate Leadership Fund, a Republican super PAC, committed to investing more than $42 million against Jackson the day Maine Democrats officially selected him as their nominee , and Collins-aligned groups have reserved almost $116 million in ads through November, compared to Democrats' roughly $57 million . - [2026-09-30] Rollcall notes Jackson's full fundraising strength remains unverified: third-quarter fundraising reports due in mid-October will be instructive on how Jackson's campaign has ramped up , meaning Jackson's resource disadvantage against Collins' battle-tested operation is a live, unresolved risk for Democrats through October. - [2026-09-30/10-01] Jackson is absorbing a self-inflicted national-politics stumble: he called Israel's response to the Oct. 7, 2023 attack a "genocide," suggested in an interview that some Mainers are uncomfortable with that label because they are Jewish, then apologized for the generalization while standing by the genocide charge , drawing bipartisan criticism just five weeks before Election Day. - [2026-09-22] Reporting on Jackson's campaign internally shows discomfort managing the issue: national Democratic consultants pushed Jackson to soften his messaging on Gaza, and at a September town hall his "word salad" response on "both sides" suffering visibly deflated the room , suggesting a more experienced, battle-tested Collins organization is exploiting Jackson's comparative inexperience on national-security messaging. - [2026-09-14] Analysts frame the structural asymmetry explicitly: Mark Brewer of the University of Maine said "she's got decades of construction experience. It's almost turnkey-ready," of Collins' campaign apparatus versus Jackson's hastily assembled one, per the Sept. 4 BDN/Maine Morning Star report. - [2026-09-22] Collins also banked a concrete local "deliverable" to tout: she took credit for securing a tariff exemption for Maine's road-salt industry, which Democratic opponent Jackson was pressed to respond to at a campaign press event (c-span.org record of Sept. 10 event), reinforcing her Appropriations-chair "brings home the bacon" message that NYT/Siena data shows resonates (59% vs 35% above). BOTTOM LINE: The strongest YES mechanism is a repeat of Collins' 2020 playbook — a late-breaking swing-voter/crossover-Democrat surge (documented now in both AARP's swing-voter breakdown and NYT/Siena's Harris-2024-voter crossover numbers) combined with a financial/organizational mismatch and a Jackson-side unforced error (the Gaza/genocide apology) eroding his standing just as undecideds begin to lock in. NOT FOUND: Confirmed Q3 (July-Sept) FEC fundraising totals for either campaign (due mid-October per Rollcall); any post-October-1 polling; independent-expenditure totals updated beyond the late-August NYT dark-money analysis; any media consensus race call.

YES means: Susan Collins wins the 2026 Maine Senate election (i.e., this market resolves Yes); this dimension argues the opposite — the strongest evidence-backed case for NO (Collins losing / Jackson winning). - [2026-08-06] A Senate Majority PAC-commissioned Hart Research poll of 800+ likely voters found 52% disapproved of the five-term senator's job performance, compared with 46% who approved , and in the same survey Collins' favorability is underwater at 48% with a favorable view and 52% unfavorable , while Jackson has a net positive favorability rating of 12 points, with 47% viewing him favorably and 35% negatively — the mechanism being that unlike 2020, Collins now starts underwater on both approval and favorability simultaneously, a genuine structural difference from the race she survived. - [2026-08-06] The same memo's author-cited comparison shows Collins' 2020 summer numbers were split evenly (48/48 approve/disapprove) versus 52/46 disapprove now, and that poll had Jackson leading by four percentage points, 49% to 45%, just over the margin of error — the NO case rests on this being a harder floor to climb out of than 2020's even-money starting point. - [2026-08-14] Axios's August 14 snapshot found The RealClearPolitics polling average has Jackson leading Collins by 2.3 points , and flagged the fundamental headwind that It is a terrible political environment for Republicans, and Maine has not voted for the GOP presidential nominee since 1988 — a generic-ballot drag that persists into fall per DDHQ's Generic Ballot D+7.9 cited elsewhere. - [2026-09-22/10-01] The ProPublica pay-to-play story has produced a tangible financial counter-reaction rather than fading: on Oct. 1 the pro-Collins Pine Tree Results PAC — whose own chairman, Scott Reed, is the subject of the allegations — reported nearly $2 million in new spending on television ads attacking Democratic challenger Troy Jackson... It was the PAC's first expenditure since late August and it follows a recent report by ProPublica alleging that its chairman, Scott Reed, discussed concealing an illegal donation from a defense contractor to a different committee that backed Collins' 2020 reelection — meaning Collins' camp had gone dark on ads for over a month while the scandal broke, a sign of campaign disruption, not momentum. - [2026-09-30] Reporting on that same PAC notes In 2020, Reed ran the 1820 PAC, which spent nearly $12 million backing Collins' reelection. Campaign finance filings show that the Pine Tree Results PAC has nearly doubled that spending this cycle — underscoring how dependent Collins is on a super PAC now under direct ethical cloud, a liability that wasn't present in 2020. - [2026-09-30] Even before the scandal, Jackson out-hauled the generic Democratic field: Democratic U.S. Senate Troy Jackson raised $5.3 million through the fundraising platform ActBlue in July, finishing third nationally among all Senate candidates despite becoming Maine's nominee in the final week of the month , and as of Oct. 1 his campaign publicly described our final end-of-quarter deadline before the election as pivotal, suggesting continued small-dollar energy rather than donor fatigue. - [2026-09-30] Outside Democratic money has scaled up in direct response to Collins' vulnerability: WinSenate, a Democratic group aligned with Senate Majority PAC, is pouring nearly $8 million into two new ads attacking vulnerable GOP incumbent Sens. Susan Collins (Maine) and Jon Husted (Ohio) , featuring a defector-voter testimonial ad, which argues the "Collins overperforms despite being outspent" 2020 narrative may not replicate given this cycle's much larger and more balanced ad war. - [2026-09-28/30] Even one of the week's "good" polls for Collins (co/efficient, an R-aligned pollster) only shows a 2-point edge, within any reasonable error band, and RCP's own late-September average Democrats have argued Collins is in a particularly vulnerable spot this cycle, even compared with 2020, when she trailed her Democratic opponent for months before eventually handily securing a fifth term. They have pointed to polls showing her underwater with Maine voters on whether she deserves another term and in her approval rating — i.e., even sympathetic commentary frames 2026 as structurally worse than 2020 for Collins, not merely a polling mirage. - [2026-09-30] A late-breaking Bangor Daily News headline from the same day as the ad-buy story flags a separate Jackson vulnerability but also signals continued hostile media narrative around Collins tied to the FBI-probe story cycle, indicating the scandal's news cycle has not fully resolved in Collins' favor as of Oct. 1. - [2025-12] Pre-existing dark-money infrastructure cuts both ways: Democratic-aligned Majority Forward (nonprofit, dark money)... has already spent money on the Maine U.S. Senate with "issue ads" targeting Collins , and historically funneled $60 million to affiliated PACs, including the Senate Majority PAC, which then spent money expressly opposing Republican candidates, including Collins , showing a durable, well-funded anti-Collins apparatus that will keep pressing through Election Day regardless of short-term poll bounces. BOTTOM LINE: The NO case rests on documented structural deterioration versus 2020 — simultaneously underwater approval and favorability (not just one), a hostile generic-ballot environment, a financially straining and scandal-linked pro-Collins PAC forced back on offense only on Oct. 1 after a month dark, and an opponent with stronger grassroots fundraising than prior Collins challengers — all suggesting Collins' famed overperformance margin of 2020 may not be reproducible this cycle even though current toplines show a true toss-up. NOT FOUND: Any post-October-1 polling, official FEC Q3 filings for Jackson's campaign (due in October), or a media-consensus race call; could not independently verify whether the Oct. 1 Pine Tree Results ad buy has moved any subsequent poll.