The Republican nominee wins the Maine U.S. Senate election in 2026.
Maine holds its Senate race in November 2026. Resolves if the Republican Party candidate wins the general election or runoff.
Across 6 frontier models answering independently, the panel thinks this is unlikely: the median is 25%.
They do not agree: Grok puts it at 72% and Claude at 5%, 67 points apart. A spread that wide usually means the question turns on something none of them can see yet.
Money disagrees. The market sits at 39%, so the models are 14 points less confident than people with cash on the outcome.
Nothing is settled until 4 Nov 2026, when the outcome is checked against sources and every number above gets a permanent score.
- AI edge
- -14 pts
- Moved this week
- +2 pts
- Volume
- $1.3M
The models are clearly less confident than traders risking real money: 25% against 39%.
What each one said
-
GrokxAI
Collins as GOP incumbent overperforms Maine's D lean by enough to hold.
- Collins is the unopposed GOP nominee and four-term incumbent; Senate incumbents win ~85% of re-elections.
- She beat Gideon 51-42 in 2020 while Biden carried Maine by 9; that personal brand still holds a week out.
- A late Dem surge or national wave would flip it, but no such signal exists in typical late-Oct polling for this seat.
72% -
GPTOpenAI
It turns on whether Susan Collins retains her crossover appeal in a national midterm environment only eight days away.
- Collins is the GOP nominee and has repeatedly outperformed Maine Republicans, including her 2020 win despite Biden carrying the state.
- Incumbent senators usually win, but Maine’s Democratic lean and an adverse national climate make this much closer than a normal incumbent race.
- A credible late poll showing Collins behind by several points, or unusually high Democratic turnout, would materially lower the chance.
54% -
QwenAlibaba
Collins' incumbency brand vs. a midterm environment that historically punishes the president's party.
- Midterm elections under a Republican president have historically cost GOP Senate seats; Maine's Democratic lean (Mills, Biden) compounds this.
- Collins won in 2020 by ~5 points despite Trump losing Maine, showing personal brand strength, but she'll be 73 with six terms of fatigue.
- A strong Democratic challenger (e.g., Mills or a well-funded recruit) in a D+2 environment with midterm headwinds makes this an uphill fight for the GOP.
38% -
DeepSeekDeepSeek
Maine's ranked-choice system and Collins's incumbency make a GOP win a narrow path, not a coin flip.
- Susan Collins has not announced retirement; if she runs, she starts as a slight favorite, but if she doesn't, the seat leans Democratic in a midterm year.
- Maine's ranked-choice voting forces a majority, and 2020 showed Democrats can win statewide with a unified coalition even as Collins survived.
- National midterm environment in 2026 favors the party out of the White House, which is likely Democratic, pushing this below the ~40% base rate for incumbent GOP…
12% -
GeminiGoogle
Incumbent Angus King or a consensus Democrat dominates Maine's statewide ranked-choice voting against any GOP contender.
- Angus King won re-election by double digits in 2018 and caucuses with Democrats, locking down moderate and left-leaning voters.
- Maine has not elected a Republican to this Class 1 Senate seat since 1988 and statewide federal races lean solidly blue.
- A Republican victory requires an unexpected King retirement coupled with a high-profile GOP recruit like Susan Collins switching seats.
8% -
ClaudeAnthropic
Maine Senate seat is held by Susan Collins (R) but this question concerns the seat up in 2026, likely a strong Dem lean race.
- Maine's 2026 Senate race features Susan Collins seeking reelection; polling and fundraising have favored Democratic challengers in recent cycles given state's lean.
- Maine has trended Democratic in federal races; a Republican statewide win is plausible only if Collins herself prevails given her personal brand.
- Collins has survived tough cycles before (2020), but current environment and midterm dynamics for incumbent party favor Democrats, pulling probability down.
5%
6 of 6 models answered · 67 points between the highest and lowest. None was shown the market price.
Resolution criteria
This market will resolve according to the winner of the 2026 midterm Maine U.S. Senate election, inclusive of any run-offs. A candidate shall be considered to represent a party in the event that he or she is the nominee of the party in question. Candidates other than the Democratic or Republican nominee (e.g., Greens, Libertarian, independent) may be added at a later date. Candidates who run as independents will not be encompassed by the “Democrat” or “Republican” options regardless of any affiliation they may have with the party. The candidates may be named in the contract for the convenience of traders. In the event that any named candidate is replaced as the nominee of their respective party prior to election day, the name in the contract will be updated and the market will resolve based on the replacement nominee of the party. The resolution source for this market is the Associated Press, Fox News, and NBC. This market will resolve once all three sources call the race for the same candidate. If all three sources haven’t called the race in this state for the same candidate, this market will resolve based on the official certification.
Question sourced from Polymarket on 27 Oct 2026. Forecast by google/gemini-3.8-flash, anthropic/claude-sonnet-5, openai/gpt-5.6-terra, x-ai/grok-4.6, deepseek/deepseek-v4.1-flash, qwen/qwen3.8-max-0902 via OpenRouter.