Senator Elizabeth Warren, Democrat of Massachusetts, on Thursday endorsed Graham Platner in the contentious Democratic Senate primary in Maine, joining a small group of progressive senators who have backed him in his race against Gov. Janet Mills.<\/p>\n
The campaign in Maine is one of the most consequential of the midterms, with Democrats aiming to unseat Senator Susan Collins, a Republican who is considered one of her party\u2019s most vulnerable incumbents<\/a>. Ms. Warren said in a statement that Mr. Platner, an oyster farmer<\/a> running as a progressive outsider, was \u201cgoing to flip Maine and then actually deliver change for working people in the Senate.\u201d<\/p>\n Ms. Warren\u2019s endorsement comes at an especially tense moment in the Democratic primary. This week, Ms. Mills released her first negative ad of the campaign, targeting Mr. Platner<\/a> over old Reddit comments he made about sexual assault.<\/p>\n The intervention by Ms. Warren is her latest split with Senator Chuck Schumer of New York, the top Democrat in the Senate, whose polling numbers have sunk<\/a> as the Democratic base turns on him for his handling of government<\/a> shutdown negotiations<\/a>.<\/p>\n Ms. Warren, who serves on Mr. Schumer\u2019s leadership team as a vice chair<\/a> of the Senate Democratic conference, has embraced candidates such as Mr. Platner who say they would not support Mr. Schumer for leader. In Maine, Mr. Schumer is backing Ms. Mills<\/a>.<\/p>\n As the biggest midterm battlegrounds take shape, Ms. Warren is expanding her political involvement: She also made endorsements this week in competitive Democratic Senate races in Iowa and Michigan, and she campaigned with Senate and House candidates in Illinois, which held a primary on Tuesday<\/a>. In January, Ms. Warren said she was plowing $400,000 from her campaign committee into midterm elections.<\/p>\n In the Democratic Senate race in Illinois, Ms. Warren backed Lt. Gov. Juliana Stratton, who had said she would not support Mr. Schumer\u2019s<\/a> remaining the party\u2019s leader in the Senate. Delivering remarks on Tuesday night at her victory party, Ms. Stratton wore a necklace reading \u201cPERSIST,\u201d<\/a> one of Ms. Warren\u2019s catchphrases.<\/p>\n Mr. Schumer called Ms. Stratton on Wednesday. They had a friendly conversation in which he congratulated her and she thanked him, said Allison Janowski, a spokeswoman for Ms. Stratton, who is an overwhelming general-election favorite in deep-blue Illinois.<\/p>\n On Thursday, Ms. Warren also endorsed Zach Wahls, a state senator, in the Democratic Senate primary in Iowa. In November, Mr. Wahls said that Mr. Schumer had \u201cfailed\u201d<\/a> the party and that it was \u201ctime for him to step down as leader of the Senate Democrats.\u201d (Mr. Wahls supported Ms. Warren in her 2020 run for president.) Ms. Warren also threw her support this week behind<\/a> Mallory McMorrow, a Senate candidate in Michigan who has said<\/a> she would not support Mr. Schumer for leader.<\/p>\n Mr. Schumer\u2019s office did not immediately comment on Ms. Warren\u2019s endorsement of Mr. Platner.<\/p>\n In Maine, where the primary is in June<\/a>, the competition is growing more heated. The contest is a contrast in generations and styles. Mr. Platner, a 41-year-old Marine veteran,<\/a> has used an active social media presence to a build a large following. Ms. Mills, 78, who has feuded with President Trump<\/a> over transgender rights, is a favorite of the Democratic establishment.<\/p>\n The support from Ms. Warren, a formidable fund-raiser,<\/a> arrives as Mr. Platner works to build on an early financial advantage over Ms. Mills. In the final quarter of 2025, the Platner campaign hauled in $4.6 million, while Ms. Mills\u2019s received $2.7 million, the campaigns reported. His campaign has spent about three times as much on TV advertising as her campaign has, according to the media tracking firm AdImpact.<\/p>\n Ms. Mills, who entered the race two months after Mr. Platner, released an ad this week depicting women reacting to comments Mr. Platner made online more than a decade ago, including one that said women worried about rape should not get so drunk that \u201cthey wind up having sex with someone they don\u2019t mean to.\u201d Mr. Platner has expressed remorse over the old comments, saying that they horrify him<\/a>.<\/p>\n Ms. Warren has been outspoken about the challenges that women face in politics<\/a>. She has described facing sexual harassment<\/a> during her career as a law professor. And she forcefully confronted a rival in the 2020 race, Michael R. Bloomberg, over his history of sexist comments<\/a>.<\/p>\n Ms. Mills\u2019s campaign responded to Ms. Warren\u2019s endorsement by noting that the governor was backed by several other prominent Democratic governors, including Gretchen Whitmer of Michigan, Andy Beshear of Kentucky and Maura Healey of Massachusetts. \u201cGovernor Mills has broad support from leaders who know what it takes to win tough races,\u201d Tommy Garcia, a spokesman for Ms. Mills, said in a statement.<\/p>\n Mr. Schumer has praised Ms. Mills, dismissing polls showing<\/a> her trailing Mr. Platner and saying last month<\/a> that she \u201cis the only Democrat who has won statewide in 20 years\u201d in Maine.<\/p>\n