Graham Platner, a Marine combat veteran turned oyster farmer, officially secured the Democratic nomination for U.S. Senate in Maine on Tuesday, defeating Governor Janet Mills in a primary that exposed deep fissures within the party and set the stage for what is expected to be one of the most closely watched general election races in the country.

The victory came despite a cascade of damaging revelations in the weeks before the vote. Just before the primary, The New York Times published accounts from three former girlfriends who described Platner as angry and erratic. One former girlfriend told the Times that Platner “regularly grabbed her by the shoulders — sometimes hard enough to leave marks” and “on one occasion, yanked her out of a cab by her wrist after an argument when she wanted to stay in the car,” the newspaper reported. Platner has denied the allegations.

Earlier, reports surfaced that Platner had a tattoo on his chest resembling the Nazi “Totenkopf” symbol. He said he got the tattoo with fellow Marines while drinking in Croatia in 2007 and did not know its meaning, later removing it. Old Reddit posts in which Platner said sexual assault victims should “take some responsibility for themselves and not get so [expletive] up” were unearthed by the Mills campaign. Platner issued an apology, asking voters not to judge him “for the worst thing I said on the internet, on my worst day 14 years ago.” He also acknowledged exchanging sexually explicit texts with women outside his marriage, saying, “At the beginning of our marriage, I made mistakes, and Amy held me accountable for them, and we worked through them.”

At a town hall in Portland on Sunday, the day before the primary, several hundred supporters packed Elks Lodge #188. A supporter presented Platner with a large handmade card signed by dozens of attendees, calling it from “your Graham-ily.” Platner appeared visibly moved and wiped away a tear. “This is a pretty hard thing to go through, to be entirely honest,” he told the crowd. “And the only thing that really makes it bearable is going around the state of Maine and having as much support as we’ve gotten.”

For many in attendance, the scandals did not diminish their support. Retiree Kevin Claik, who drove 30 miles from Naples to see Platner, said, “He’s got a fantastic platform. He’s got a little bit of baggage, but who gives a shit? He is a saint here to me.” Autumn Crisovan, a Portland resident who works in recreational sports, described herself as “really excited for what the momentum that an unbought candidate might mean for the rest of the country.”

Platner’s rise has been fueled by a grassroots network that his campaign said includes 11,000 volunteers and a total fundraising haul of more than $14 million. He has drawn on the energy of Maine’s small-town political culture — the state has just 1.4 million residents — and a message that mixes populist anger at entrenched wealth with a working-class biography. “That hardscrabble work, that incredibly hard work that Mainers have been proud of doing for generations, it used to be enough,” Platner said of his state’s past economic promise.

His policy platform is drawn from the progressive wing of the party: universal government-provided healthcare, free college education, and a wealth tax. He frequently praises Vermont Senator Bernie Sanders and New York Congresswoman Alexandria Ocasio-Cortez on the stump. As he puts it, his campaign is not about him but about “the people of Maine” — a pitch that mirrors the anti-establishment appeal that has animated candidates from both parties in recent years.

The general election pits Platner against Collins, a Republican who has not lost a Senate race since her first election in 1996. Collins has outlasted Democratic challengers in a state that has voted for the Democratic presidential candidate in every election since 1988. She holds a large financial advantage: her campaign and affiliated committees reported more than $20 million on hand, dwarfing Platner’s $2.7 million. But Platner has developed a national donor base, and his campaign has raised more than $14 million overall.

A survey conducted by conservative pollster Tony Fabrizio for the Collins campaign, described in an internal memo printed by Politico, found that the latest revelations had driven Platner’s negative rating among Maine voters from 29% to 49%. Even so, the race was tied at 46%. “It is clear that the more voters learn about Platner the more they find they don’t like him, making the Senate race highly competitive,” Fabrizio wrote.

Some Democratic voters expressed deep ambivalence. Portland resident Ann Oliver said, “I’m not changing my vote, although I hate him for it. … I would vote for him exclusively to keep Susan Collins from winning.” Platner’s former political director, Genevieve McDonald, wrote an opinion piece in The Washington Post on Monday warning that Platner “exhibits a pattern of dishonest behavior that is impossible to ignore.”

Support from within the party has been mixed. Democratic Congressman Ro Khanna of California campaigned with Platner in Bar Harbor the day after The New York Times story appeared. In a Sunday interview on NBC News, Khanna said, “I believe what he did was wrong, was misogynistic, was toxic or volatile. I know he’s ashamed of it, and I certainly think it would be appropriate to apologise and say how he now understands why it’s important to stand up to a misogynistic culture.”

Amanda Litman, who founded the candidate-recruitment group Run for Something, said voters will forgive a lot as long as a candidate is honest about change. But she noted that the cascade of fresh allegations risked betraying the trust Platner had built through his redemption narrative.

The outcome in November will be closely watched as a bellwether for whether the Democratic Party’s progressive insurgents can compete in battleground states — or whether, like the Tea Party movement a decade ago, they risk nominating candidates who energize the base but alienate the broader electorate needed to win general elections. “If you believe, as I do, that we can change our politics and our country,” Platner told supporters on Tuesday night, “then you must also believe that people can change. The reason I believe that is because I have lived it.”