A contentious Democratic primary is unfolding in Maine as two very different candidates vie for the chance to challenge five-term Republican Sen. Susan Collins, whom Democrats see as one of their best pickup opportunities this cycle.
The race pits centrist Gov. Janet Mills, 78, against progressive outsider Graham Platner, 41, an oyster farmer, military veteran and former private contractor. Mills emphasizes her statewide record and long experience in elected office; Platner casts himself as a change agent and frames the contest as a generational battle between ‘‘old ideas’’ and ‘‘new ideas.’’
Public polling is limited, but some recent surveys show Platner leading among likely Democratic primary voters. Fundraising so far favors Platner: federal filings show he raised roughly $7.8 million last year, compared with about $2.6 million for Mills. Collins has reported about $4.6 million, while longshot Democrat David Costello has raised roughly $21,000, not counting loans. Given the national stakes, outside groups are expected to pour money into the race as it intensifies.
The primary has grown increasingly negative. Mills’ campaign recently launched a statewide ad buy that highlights a series of controversial Reddit posts attributed to Platner, including an old 2013 comment critics say blamed victims in a sexual-assault context. Platner has apologized for many of the posts, saying they reflect an earlier, troubled period of his life; in an October video he called the remarks embarrassing and attributed some language to crude military humor and to struggles with depression and PTSD following deployments to Iraq and later Afghanistan with the National Guard.
Other reporting uncovered additional online entries in which Platner used profanity about police, described himself as a communist, and made comments interpreted as disparaging toward rural White people. He also faced scrutiny over a tattoo that resembled a Nazi symbol; Platner says he got the tattoo nearly 20 years ago during a night of heavy drinking in Croatia, has covered it up, and did not realize its connotations at the time.
Both Democrats have focused much of their public messaging on Collins. Mills, a former district attorney and attorney general who won reelection as governor in 2022 with about 55 percent of the vote, was a top recruit for Senate Democratic Leader Chuck Schumer and has highlighted her record and electability. She won national attention last year after a public exchange with former President Trump in which she told him ‘See you in court’ following threats to cut funding to Maine.
Platner has run an insurgent campaign appealing to progressive and populist voters, arguing Democrats need a more confrontational nominee willing to challenge Republicans and party leadership. He has won endorsements from Sen. Bernie Sanders, Sen. Ruben Gallego, the United Auto Workers and the Maine State Nurses Association.
Collins, who has represented Maine for nearly three decades, has positioned herself as a moderate willing to break with GOP leaders and with Trump. She remains a formidable general-election candidate because of deep local ties and a history of statewide success, even as Maine leans Democratic — former President Trump lost the state by about seven points in 2024. Flipping Collins’ seat would still be difficult: Democrats must win multiple Republican-held seats to reach a majority in the Senate.
The combination of a vulnerable incumbent, a high-profile recruit, sharp intra-party debates and uncertainty over who can best defeat Collins has made Maine one of the most closely watched Senate contests this cycle. The Democratic primary winner in June will take on Collins in the general election.