The Maine U.S. Senate race has rapidly transformed into one of the nation’s most closely watched political showdowns, as Governor Janet Mills’ official entry into the Democratic primary on October 14, 2025, set off a cascade of reactions, endorsements, and strategic maneuvering across the political spectrum. With Republican Senator Susan Collins aiming for a sixth term, the contest has become a litmus test for the future direction of the Democratic Party—pitting seasoned establishment leaders against a surging grassroots movement eager for generational change.
Mills’ entry into the race was far from a quiet affair. Backed by national Democratic leaders and seen as a top-tier recruit, her campaign launch immediately prompted the Cook Political Report to shift its rating of the Maine Senate contest from “lean Republican” to “toss-up.” As Amy Walter, editor in chief and publisher of the Cook Political Report, put it, “For the first time since she was elected in 1996, Collins could face off against a sitting statewide officeholder who, like her, has a proven track record of outperforming the presidential ticket of her party.” Walter also noted, “Mills, of course, does not have a clear path to the nomination, and there is no guarantee that she will win it. But she is a top-tier recruit in a field that currently lacks a well-known or well-established candidate.”
Mills, age 77, boasts a formidable record, having secured more than half the statewide vote in her last two gubernatorial elections. Her campaign is being championed by Democratic leadership in Washington, including Senate Minority Leader Chuck Schumer, who personally recruited her for the race. Yet, her entry has also exposed deep rifts within the party—especially between the establishment and a rising progressive wing energized by younger voters and activists.
Leading that insurgent charge is Graham Platner, a 41-year-old oyster farmer and military veteran from Sullivan. Platner’s campaign, which has held more than twenty town halls across Maine, is rooted in a message of economic populism and deep skepticism of establishment politics. “I have held over twenty town halls in every corner of Maine, from Rumford to Madawaska to Portland. Everywhere I hear the same thing: people are ready for change,” Platner said in a statement on Tuesday. “They know the system is broken and they know that politicians who have been working in the system for years, like Susan Collins, are not going to fix it.”
Platner’s bid has attracted significant grassroots momentum. On the same day Mills announced her candidacy, a coalition of youth-focused Democratic groups—including Leaders We Deserve, Voters of Tomorrow, College Democrats of America, Gen-Z for Change, and Youth Save Democracy—threw their support behind Platner. David Hogg, former DNC vice chair and founder of Leaders We Deserve, summed up the mood: “After our historic loss in the 2024 election, conversations within the Democratic Party have rightly centered on age, the loss of young men, the working class, and the growing disillusionment of young voters. As our party charts a path forward, Graham Platner represents not the entire solution, but a vital step in the right direction.”
The generational divide is palpable. Sunjay Muralitharan, national president of the College Democrats of America, said, “While College Dems deeply appreciate the efforts of Janet Mills to stand up to MAGA’s fascism, our party is in deep need of a new generation of leadership. We require leaders with utmost authenticity and clear principles, ones that we can trust to fight for us. Graham Platner is that leader.” Santiago Mayer, executive director of Voters of Tomorrow, added, “The status quo has failed young people and we’re done settling for politics as usual. Gen Z wants leaders who will fight unapologetically for our future. Graham Platner is ready to meet that moment.”
Platner’s campaign has also garnered the endorsement of independent Vermont Senator Bernie Sanders and has raised $4 million since its August 2025 launch—a remarkable sum for a first-time candidate. Sanders, never one to mince words, criticized Mills’ entry as potentially divisive and costly for Democrats. “It’s disappointing that some Democratic leaders are urging Governor Mills to run,” Sanders wrote on social media earlier this month. “We need to focus on winning that seat & not waste millions on an unnecessary & divisive primary.”
The Democratic primary is already proving to be combative. On the heels of Mills’ announcement, Platner released his first television advertisement, which began airing statewide on MSNBC on October 15. The ad, a six-figure buy running for three weeks, features Maine residents expressing a desire for change. “Janet Mills again? She was a good governor, but I think it’s time for change,” an older woman says in the spot. Another woman quips, “Maybe he could shuck up the system,” highlighting Platner’s oyster-farming background. The ad positions Platner as a “change agent” and someone ready to “take it to Trump,” echoing both his and Mills’ promises to confront the former president. Mills, for her part, has highlighted her own record of standing up to Trump in her campaign materials.
The crowded Democratic field has seen some candidates stepping aside. Dan Kleban, co-founder of Maine Beer Company, suspended his campaign and endorsed Mills, stating, “While our message was right, the timing isn’t. Governor Mills is the right leader for this moment and is in the best position to win.” Others, like David Evans, an Army veteran and former Pentagon policy writer, and Tucker Favreau, a cybersecurity professional and Army veteran, remain in the race. Evans emphasized, “Janet Mills and I both care deeply about Maine. I look forward to a primary focused on solutions, not divisions and on delivering real solutions at the national level.” Favreau, while energized by Mills’ entry, critiqued her decision: “She could have helped mentor multiple candidates throughout this race and helped Maine Democrats build a deep bench of candidates for multiple future races. Instead, she has chosen to run for a position which she would likely only be able to occupy for one term.” Mills herself has pledged, according to an interview with the Boston Globe, to serve only one term if elected to the Senate.
Meanwhile, Republicans are closely watching the Democratic infighting. Alex Latcham, executive director of the Senate GOP’s top super PAC, called the Maine Democratic primary “increasingly toxic,” and praised Collins’ “effective and proven leadership.” Collins, 72, has not officially announced her reelection bid but has told Maine Morning Star she intends to run and has already raised millions. Maine Republicans have largely closed ranks behind Collins, rejecting a primary challenge, though two longshot GOP contenders remain.
Political analysts see both opportunity and risk in the Democratic primary. Mark Brewer, chair of the political science department at the University of Maine, noted, “Voters have a bigger menu of options to choose from, while candidates get campaign experience before the general election, including debates. That can be beneficial, especially for inexperienced candidates.” But he also warned that a bruising primary could “deplete resources—money, staff—for the general election” and provide ammunition for Collins in November.
With nearly nine months until the primary, the battle lines are clearly drawn. Mills, representing establishment experience and electability, faces Platner’s insurgent, youth-driven campaign. The stakes are high—not just for Maine, but for the national political landscape as Democrats grapple with questions of generational change, party unity, and how best to challenge the GOP in a polarized era. As the campaign heats up, Mainers (and the rest of the country) will be watching closely to see which vision prevails.
