Progressive takes commanding lead in new poll in high-stakes Senate primary

The progressive candidate Graham Platner has a commanding lead in the Democratic primary for Maine’s US Senate seat over the state’s centrist Gov. Janet Mills. Come November, he’s also much more likely than Mills to defeat the Republican incumbent, Sen. Susan Collins.

The University of New Hampshire’s Pine Tree State Poll, released Tuesday morning, showed that Platner has built momentum since October. Five months ago, 58% of likely Democratic voters said the 41-year-old oyster farmer was their first choice to be the state’s next senator, compared with 24% who preferred the governor.

Now, with the June primary less than four months away, undecided voters have broken hard in Platner’s favor: 64% said he’s their first choice, while Mills has only jumped up to 26%.

It’s perhaps an unsurprising result, as Democratic voters overwhelmingly support the kind of economically populist anti-oligarchy politics that Platner—a proponent of Medicare for All and a federal billionaires’ tax, with backing from labor unions and Sen. Bernie Sanders (I-Vt.)—has unapologetically championed.

But Tuesday’s poll suggests his message is not only resonating with Democrats. Where a race between Mills and Collins has the Democrat leading by a single point, within the margin of error, Platner would be expected to win the general election comfortably with 49% of the vote to just 38% for Collins.

The steady shift toward Platner comes as affordability issues have become increasingly salient to Maine voters. A full 35% of voters said that either the cost of living or housing was the most important problem facing Maine.

As President Donald Trump suffers historic unpopularity amid a flailing economy, the most marked shift has been concern about the cost of living. Where just 4% of Mainers said it was their No. 1 issue in March 2025, that number has shot up to 20% this month.

Collins’ popularity has been in a dramatic freefall in the era of Trump 2.0, to the point where a late January Morning Consult poll showed her to be the second-least popular US senator, behind only the former longtime GOP leader, Sen. Mitch McConnell (R-Ky.).

While Democratic Party insiders have long argued that voters prefer a safer, moderate candidate when ousting a hated incumbent, observers say Platner’s success over the candidate backed by Senate Minority Leader Chuck Schumer (D-NY) and much of the party establishment is redefining what it means to be “electable” in a swing state.

“The fatal part of this poll for Mills isn’t even the massive lead Platner has,” saidDrop Site News co-founder Ryan Grim. “It’s that he is 10 points more electable against Collins, which is the real priority for Maine voters who don’t want her in office anymore.”

New York Timescolumnist David Wallace-Wells said: “This is a small-sample poll, and there’s a long way to go. But if something like this comes to pass—Platner stomping Mills in the primary, then cruising to a double-digit win in the general election—it wouldn’t just be a Senate-seat victory but a narrative earthquake.”