A new survey of Maine’s Democratic Senate primary shows Graham Platner holding a lead over Governor Janet Mills as the party decides who will challenge Republican Senator Susan Collins in what’s expected to be one of the tightest races of the 2026 midterms.
Why It Matters
Democrats see Maine as one of their best opportunities to unseat a longtime Republican incumbent. Collins has maintained strong support in the state, even as Maine has leaned Democratic in recent election cycles. The matchup between Mills and Platner has split opinion within the party.
Supporters of Mills point to her two comfortable statewide victories in the 2018 and 2022 governor’s races as evidence she’d be the safest bet against Collins. Platner’s backers argue he represents a new generation of leadership and would offer voters a sharper contrast in November.
Maine is also a key part of Democrats’ path to reclaiming the Senate majority. Collins is the only Republican senator up for reelection in a state carried by former Vice President Kamala Harris. The only other GOP-held seat in a state that former President Donald Trump won by single digits is the North Carolina seat being vacated by Senator Thom Tillis.
With Republicans currently holding a 53–47 edge in the Senate, Democrats would likely need to win both of those seats—and pick up wins in more conservative states—to retake control.
What to Know
The poll from Z to A Research found Platner leading Mills by double digits among Democratic primary voters. Fifty-eight percent of respondents said they would back Platner, while 38 percent said they supported Mills.
Platner’s strongest backing came from voters under 50, with 77 percent of that group saying they preferred him over Mills.
Mills was viewed favorably by 69 percent of respondents and unfavorably by 20 percent. Platner was seen favorably by 63 percent and unfavorably by 15 percent. The survey included 1,482 likely midterm voters and was conducted from November 14–18.
The poll did not test general election matchups against Collins.
Both Mills and Platner have attracted national attention and endorsements. Mills has received support from Senate Minority Leader Chuck Schumer of New York, as well as Democratic Governors Andy Beshear of Kentucky and Gretchen Whitmer of Michigan. Platner has been backed by prominent progressives, including Senator Bernie Sanders of Vermont and Representative Ro Khanna of California.
Other polling has painted a more mixed picture of the primary.
A survey from Maine People’s Research Center suggested a much closer contest, with Platner ahead of Mills by just two points, 41 percent to 39 percent. Nearly 20 percent of respondents either supported another candidate or were undecided. That poll surveyed 783 Maine voters from October 26–29 and had a margin of error of plus or minus 3.5 percentage points.
Another poll, from SoCal Research Center, showed Mills with a 5-point lead, 41 percent to 36 percent. It surveyed 500 likely primary voters from October 21–25.
Platner has also had to contend with a series of controversies over old Reddit posts about sexual abuse survivors and rural white Americans, as well as a tattoo resembling the Totenkopf, or “death’s head,” a symbol associated with Nazis.
He has apologized for both the posts and the tattoo. Platner told the Associated Press he has since covered the tattoo and said he did not realize the symbol’s connection to Nazism. He told CNN the posts were “very much me f****** around the internet.”
What Happens Next
Maine’s Democratic primary is scheduled for June 9, 2026. Election forecasters expect the general election to be highly competitive: both the Cook Political Report and Sabato’s Crystal Ball currently rate the race as a toss-up.
