Will the Democrats win the Maine Senate race in 2026?

TL;DR

The saved forecast is Yes 56.9% and No 43.1%. The Democratic nominee, Troy Jackson, has a small edge in the direct evidence, especially the late polling average and several October surveys. Susan Collins remains fully capable of winning because Maine has already seen her beat a polling consensus by a wide margin.

Context

This is a direct contest between Democratic nominee Troy Jackson and Republican incumbent Susan Collins. Jackson became the Democratic replacement nominee in July after the original nominee withdrew (AP News). The ballot is effectively a two-candidate Senate race, so the question is chiefly whether Jackson can hold a narrow polling advantage through Election Day rather than whether a substantial third-party vote changes the outcome (Suffolk).

The race sits in the final two weeks of the campaign. That makes direct measures of vote intention more useful than broad political narratives. But this is also precisely when a narrow polling advantage should be treated as a narrow advantage. The forecast does that: it puts Democrats ahead, without treating the result as settled.

Evidence

The historical backbone is Collins’s record as an unusually strong Maine Republican. In 2020, Collins won 51.0% to Democrat Sara Gideon’s 42.4%, an 8.6-point victory, even though the final polling picture had generally favored Gideon (RealClearPolling). The relevant lesson is not that the same error will recur. The candidates, national setting, electorate, and ballot differ. The lesson is narrower and more useful: a small Democratic polling lead against Collins should carry more uncertainty than a comparable lead against a conventional incumbent.

The current public evidence nonetheless leans toward Jackson. RealClearPolling’s late series, using polls fielded from September 23 through October 14, has Jackson at 48.8% and Collins at 47.2%. That is a Jackson margin of 1.6 points (RealClearPolling). Its list contains a mix of Jackson leads, ties, and a Collins lead. The signal is not a one-survey outlier. It is a modest, persistent Jackson advantage.

The available late polling history is as follows:

Field dates	Poll	Population / sample	Result
September 15–22	NYT/Siena	619 likely voters	Collins 49%, Jackson 46% (Siena Research Institute)
September 17–21	UNH Pine Tree State Poll	1,312 likely voters	Jackson 51%, Collins 47% (Political.org)
September 20–22	Fabrizio Ward / Impact Research for AARP	982 likely voters	Jackson 50%, Collins 47% (AARP)
September 23–October 1	CBS/YouGov	1,144 registered voters	Jackson 50%, Collins 50% (CBS News)
September 30–October 5	Washington Post/Schar School	800 likely voters	Jackson 50%, Collins 46% (Washington Post)
October 1–4	Marist	1,505 registered voters	Jackson 51%, Collins 47% (Marist)
October 5–8	Rasmussen	804 likely voters	Jackson 49%, Collins 47% (Rasmussen Reports)
October 8–11	Suffolk	500 likely voters	Jackson 49%, Collins 47% (Suffolk)
October 13–14	InsiderAdvantage	1,200 likely voters	Jackson 49%, Collins 47% (US Polling Data)

The table shows why Jackson is favored but not by much. The newest three listed polls all show Jackson ahead by two points. Washington Post/Schar and Marist show larger Jackson leads. Yet CBS/YouGov is tied, and NYT/Siena gives Collins a three-point lead. The most defensible reading is a close race with Jackson a little ahead, not a race in which polling establishes a stable multi-point Democratic lead.

Suffolk is especially useful because it surveyed likely voters late in the campaign and used live telephone interviews. Its Jackson 49%–Collins 47% result included 3.8% undecided and 0.2% refusing (Suffolk). Its sample size also limits what can be inferred from two points. The result supports a slight Jackson edge. It cannot rule out a narrow Collins lead.

The state environment gives Jackson support. Marist found Trump at 40% approve and 59% disapprove among Maine registered voters. It also found Democrats ahead 54%–45% on the generic congressional ballot (Marist). The same survey placed the Democratic gubernatorial candidate 12 points ahead, while Jackson led Collins by four. That gap shows that the state is not treating this Senate race as a simple referendum on national party control.

The Washington Post/Schar survey points in the same direction. It reported a 36% Trump approval rating among likely voters and found a 55% preference for Democratic Senate control. It also found Jackson ahead on several issue measures, including abortion, cost of living, health care, corruption, and understanding Maine voters (Washington Post). These are favorable conditions for a Democratic challenger. They help explain why Jackson is ahead rather than tied or behind.

But Collins has a personal-vote cushion that the generic environment does not capture. CBS/YouGov found that she won support from roughly one in five voters who disapproved of Trump, and that some voters supporting the Democratic gubernatorial nominee were splitting their tickets for Collins (CBS News). Collins also led on bringing federal funding to Maine and on bipartisanship in Washington Post/Schar polling (CBS News). Those are practical reasons a voter can dislike national Republicans and still back the incumbent.

Late-campaign indicators are mixed. Party enrollment in returned absentee ballots leaned Democratic: a tracker using the Maine Secretary of State’s October 16 file reported roughly 53% Democratic-enrolled returns, 19% Republican-enrolled returns, and 25% unenrolled returns (Call the Map). This is mildly favorable to Jackson. It is not a vote count. Maine has many unenrolled voters, and Collins has demonstrated appeal beyond registered Republicans.

Money is a small Collins-positive factor. Jackson raised nearly $20.4 million after becoming nominee, but ended September with less cash on hand than Collins and about $1 million in debt. Collins held just under $5.4 million in cash (News From The States). Republican-aligned outside spending against Jackson has also been substantial (PaidForPolitics). Resources can matter at the margin, especially in a close late race, but the polling available after that spending still shows Jackson narrowly ahead.

The October 15 debate incident, in which Jackson told Collins to “shut up,” is another small Collins-positive risk rather than a decisive event (AP News). It could provide an effective message for voters focused on demeanor. There is no direct evidence in the supplied record that it has moved the ballot. It should therefore widen caution, not displace the more informative direct vote data.

What's non-obvious

The obvious read is that a Democratic statewide environment should make Jackson comfortably favored. That misses the difference between Maine’s party climate and this candidate matchup. The generic ballot, Trump approval, and governor’s race all look better for Democrats than the Senate ballot does. Collins’s crossover vote is the reason. The forecast gives Democrats the edge because the Senate polls themselves lean Jackson, but it does not use the broader environment as if it were a substitute for the Senate vote.

The other easy mistake is to replay 2020 mechanically. Collins’s polling outperformance is genuine and highly relevant. But subtracting the full 2020 error from Jackson’s current margin would assume that every source of that miss repeats. The cleaner interpretation is that 2020 raises the chance that a narrow Jackson lead is misleading. It does not erase the current run of October polling that favors Jackson.

Uncertainties

The largest uncertainty is correlated polling error. The polls are not independent draws from separate electorates. They may share errors in measuring turnout, nonresponse, or Collins’s crossover support. This matters far more when the average lead is 1.6 points than when it is large.

Several specific gaps remain:

• There is no confirmed post-debate poll in the supplied evidence, so the effect of the October 15 exchange cannot be measured directly.
• Absentee-return data identify party enrollment, not candidate choice. They are especially incomplete as a guide to a race involving Collins and many unenrolled voters.
• The latest finance information covers activity through September 30, leaving uncertainty about final-week advertising and field activity.
• The NYT/Siena Collins lead and the other polls pointing to Jackson cannot be reconciled with certainty from the available material.

These uncertainties are why the forecast remains Yes 56.9% and No 43.1%, rather than a stronger Democratic probability. The available evidence says Jackson has the better chance. It also says Collins has a clear and credible path to win.