Maine senate odds: Jackson 72.5% vs Collins on Polymarket

Maine senate odds have flipped hard toward the Democrats on the eve of Election Day. At our 06:04 UTC snapshot (09:04 MSK) on November 2, Polymarket priced a Democratic win in Maine at 72.5% and a Republican win at 27%. That puts Troy Jackson well ahead of five-term incumbent Susan Collins in the market, a result that would have sounded wild a year ago.

What actually happened

The Democratic side of this race had a messy path. Graham Platner won the June 9 primary with 72.1% but withdrew in July, PollingSource notes. Maine Democrats then picked Troy Jackson at a state convention in Bangor on July 25.

Since then the polls have moved his way. PollingSource's average of the last three scientific polls, from NYT/Siena, UNH and YouGov, shows Jackson at 52.3% and Collins at 45.7%, a D+6.6 margin. The site now rates the race "Likely D," after it sat at "Tilt Republican" until mid-September.

The UNH Survey Center summed up the mood with a twist. Jackson leads the horse race, but most Maine voters think Collins will win anyway. Collins has a long record of beating bad polls, and that memory still shapes how locals read the numbers.

What Polymarket thinks

The Maine senate odds at 06:04 UTC:

• Democrats win Maine: 72.5% Yes (bid 72, ask 73)
• Republicans win Maine: 27% Yes

Maine also uses ranked-choice voting, so a first-round result under 50% could trigger later rounds. Polymarket runs separate margin markets on the first round, but the winner market above is the cleanest read.

For the national picture, Polymarket gives Democrats 72.5% to control the Senate. CoinDesk notes Democrats need at least four more seats, so Maine is one of the seats that market almost certainly counts on. We broke down the overall map in senate 2026 democrats.

Markets at 72% are not certainties. Roughly one in four times, the 27% side wins.

Why Collins is still dangerous

Start with the money. The Republican side of the market has drawn about $1.5 million in volume on its own, which means plenty of traders still see value in betting on a Collins comeback at these prices. Thick two-sided volume like that is a sign of real disagreement, not a sleepy market.

Collins has outperformed her polls before, and local voters remember it. The UNH finding that most Mainers expect her to win is a real signal of how sticky her brand is.

Polling in a small, rural state is also harder. Turnout models matter a lot, and UNH notes that Democrats have nationalized this election as a referendum on President Trump. If Republican turnout beats expectations, the gap could close fast.

The CNBC investigation published October 30 adds a broader caution. It found that about 23% of congressional markets worth more than $100,000 on Polymarket International and Kalshi saw price spikes of 30 cents or more at some point. Election prices can move on order flow, not just news.

How this fits the Senate map

We have tracked other key races in alaska senate odds and texas senate odds. Maine is different because the market already treats it as a likely Democratic pickup, so an upset would hit the Senate control market hard.

Polymarket also lists combo markets. For example, "Republicans win Texas, Michigan and Maine" traded near 13% at our earlier check. Those combos show how traders link outcomes across states.

What to do as a reader

Watch early returns from Maine's southern counties against expectations, and remember that ranked-choice tabulation can take longer if nobody clears 50%. The Maine senate odds can swing on partial counts, so do not overreact to the first few percent of votes.

Check the live Polymarket Maine market before doing anything, because our snapshot is already old by the time you read this. Election markets often move several points within minutes on election night.

Treat this as information, not a tip. Nothing here is investment advice, and prediction market positions can go to zero.