A new poll shows two-term incumbent Gov. Janet Mills trailing political newcomer Graham Platner in the Democratic primary for U.S. Senate.

The Pan Atlantic Research 68th Omnibus Poll shows Platner with a 7-point lead — a 17-point swing from the firm’s last survey, which showed Mills up 10 points in December. But the survey showed the governor with a 31-point advantage in the more rural, conservative 2nd Congressional District.

The new poll, conducted from Feb. 13 to March 2, showed 46% of likely Democratic primary voters would choose Platner, while Mills netted 39% support. Eleven percent were undecided.

The survey included responses from a small sample — 367 likely primary voters — and had a margin of error of +/- 5.7 points.

Platner is a 41-year-old oyster farmer and combat veteran who has never held elected office, and Mills is a 78-year-old career public servant.

The poll shows Mills tied with five-term Republican incumbent U.S. Sen. Susan Collins in a hypothetical general election matchup with 12% undecided, while Platner leads Collins, 44% to 40%, with 16% undecided. That sample included 810 respondents, and had a margin of error of 3.7%.

“The top priority in 2026 is defeating Susan Collins — and this is yet another poll that shows Graham outperforming the Governor in head-to-heads against Susan Collins,” said Platner campaign spokesperson Charlie Hills. “The numbers make clear that he is the best-positioned candidate to win the general.”

Platner’s net favorability rating of +14 points is also much higher than Mills, who came in at -6 points. But a significant number — 30% of the 810 people asked — said they did not know enough about Platner to offer an opinion.

Collins’ favorability rating was -14 points.

Mills campaign spokesperson Tommy Garcia said the poll shows a competitive race, with Mills performing stronger in the 2nd District, where a strong showing will likely be needed in the general election.

“Janet Mills is the only Democrat in this race who has actually won statewide, not once but twice, and by increasing margins,” Garcia said in a written statement. “Janet Mills is going to fight for every vote, just as she has always done, and she’s going to win both the primary and the general.”

The Pan Atlantic poll comes one week after a survey by the University of New Hampshire showed Platner with a 38-point lead over Mills.

Platner is outpacing Mills among men and voters under the age of 54, the survey found, while remaining competitive among women and older voters. Fifty-two percent of men chose Platner, as did 61% of voters aged 18-34.

Mills and Platner are tied at 41% among women, while Mills has a slight advantage with voters age 55 and older, 43% to 40%.

The poll also showed Platner with strong support among independents (56% to 23%) and people with incomes over $100,000 (56% to 32%.)

But the poll includes one warning sign for Platner. Voters in the 2nd District prefer Mills, 54% to 23%. Platner leads in the more liberal 1st District.

In the governor’s race, the poll found that 44% of the 298 likely Republican primary voters said they were not familiar with the candidates.

Bobby Charles, a former U.S. assistant secretary of state, currently leads in the Republican primary, with 26% support. He’s followed by former Senate Majority Leader Garrett Mason (11%), state Sen. James Libby (8%), Owen McCarthy (7%) and David Jones (6%). Jonathan Bush and Ben Midgely each had 4%, the survey found.

On the Democratic side, former state health official Nirav Shah and Angus King, III were tied at 24% among the 367 likely primary voters. They were followed by former state House Speaker Hannah Pingree (18%), Secretary of State Shenna Bellows (16%) and former state Senate President Troy Jackson (10%).

Pingree and King had the highest percentage of people open to supporting them at 48% and 47%, respectively.

The poll also tested the candidates in the race for the 2nd Congressional District.

In CD2, 38% of the 144 likely Democratic primary voters were undecided, while 36% supported state Sen. Joe Baldacci, 14% favored state auditor Matthew Dunlap and 12% chose Jordan Wood.

Former two-term Gov. Paul LePage likely awaits the winner of that primary.