PORTLAND, Maine — At a packed rally Saturday, Sen. Elizabeth Warren, D-Mass., called on voters to support political newcomer Graham Platner in a closely watched Democratic primary to challenge longtime Republican Sen. Susan Collins.

Subscribe to read this story ad-free

Get unlimited access to ad-free articles and exclusive content.

“I’m here because Washington needs fighters, and Graham Platner is the fighter we need,” Warren told the crowd. “Graham is a combat veteran. He’s an oyster farmer, he is an organizer, and he is the person who is going to beat Susan Collins.”

The primary has divided the party: Warren and Sen. Bernie Sanders, I-Vt., are backing Platner, but Senate Minority Leader Chuck Schumer, D-N.Y., is supporting two-term Gov. Janet Mills.

The winner will take on Collins in November in a must-win race for Democrats in their battle for Senate control this fall.

Platner leads Mills by 33 points in a recent poll of likely voters taken by Maine People’s Resource Center. He leads by 27 points in a recent Emerson College poll.

He told they crowd that voters “must dream big” and organize to upend modern politics, arguing that the existing system has exacerbated economic inequality and harmed the working class.

“We continue to do the hard work that we and those before us have been so proud of for generations, but it ceased being enough. And all of it happened when we watched the largest transfer of wealth from the working class to the ruling class in the history of this nation,” Platner said. “The money went somewhere, and it wasn’t down here. It was stolen from us, stolen from us in a system that was built by establishment politicians like Susan Collins.”

“We need to be willing to understand that we’re all being exploited by the exact same people,” he said. “And it’s not immigrants, it is not trans kids, it’s billionaires.”

Some Democrats worry about Platner’s history of controversial and offensive remarks, including a series of Reddit posts years ago downplaying sexual assault. He has apologized for those comments and said he’s changed his outlook. His skeptics also cite one of his tattoos, which Platner recently had covered after saying he just learned that it had Nazi associations.

Platner, a combat veteran, took aim at President Donald Trump and his recent military actions.

“The war in Iran and Venezuela — these things were uniquely stupid,” he said. “Somehow, Donald Trump and Pete Hegseth might be the dumbest people to ever run a war — which is saying something, because throughout history, many wars have been done have been run by monumentally dumb people.”

Warren, a former presidential candidate, has defended Platner and said he has learned from his mistakes. She told the crowd here that he won’t “bend a knee to the big corporate donors, to the billionaires who don’t want to have to pay“ higher taxes to fund Social Security and build a safety net.

“The path to the majority for Democrats in the United States Senate runs right through Maine,” Warren said. “This is it. This is the all-hands-on-deck moment from now until November.”

Platner’s wife, Amy Gertner, introduced Warren and Platner.

“If you had told me one year ago that I would be on stage where Elizabeth Warren is about to speak and say that she wants to serve in the United States Senate with my husband, I would have laughed you out of the room,” Gertner, a teacher, told the crowd.

Platner, for his part, said it’s not enough just to flip the Senate.

“We all want to get rid of Susan Collins. We all want to turn Maine blue,” he said. “But it very much matters what kind of Democrats we turn the Senate blue with.”