In recent days, union leaders have urged Senate Minority Leader Chuck Schumer, D-N.Y., and the Democratic Senatorial Campaign Committee to halt their support of Gov. Janet Mills in Maine’s Senate primary, citing their perception of her poor performance against the Labor Party.
Two people familiar with the matter told NBC News that UAW President Sean Fein had a conversation with Schumer this month to discuss the campaign and other topics. The UAW endorsed Mills’ opponent, Democrat Graham Plattner, while Schumer and the DSCC endorsed Mills.
Fein discussed with Schumer what he saw as “shortcomings” in Democratic leaders’ approach to the 2026 midterm elections, “particularly their failure to adequately listen to working-class voters,” a person familiar with the matter said. Fein pointed to the Maine game as an example, this person said.
Separately, on Monday, Michael Monahan, international vice president of the International Brotherhood of Electrical Workers District 2, which includes Maine, sent a letter to DSCC leadership “expressing our deep concern about DSCC’s continued involvement in the 2026 Maine Democratic Senate primary” (NBC News obtained the letter).
“We strongly urge the DSCC not to further interfere with this primary election,” Monahan wrote, adding, “Your committee’s support of Janet Mills is upsetting to our membership for several reasons.”
Monahan called Mills’ relationship with the union “concerning.” He pointed to polls showing Plattner ahead of Mills and argued that money spent on Plattner could undermine his ability to take on Republican Sen. Susan Collins in the general election.
The race in Maine may be Democrats’ best chance to flip a Republican-controlled Senate this fall, and they must win to have a chance to take over the House. While the national Democratic establishment has rallied behind Mills, Labor’s push underscores base voter dissatisfaction with the decision, as well as Platner’s resilience through the controversy.
Platner announced her candidacy in August and Mills joined two months later, setting off a primary that reflected generational and ideological divisions in the Democratic Party.
A mid-February University of New Hampshire poll found Plattner ahead of Mills among likely Democratic primary voters by 38 points, well outside the survey’s margin of error. The Mills campaign questioned the survey in a memo, pointing to other recent missteps in the survey in Maine and arguing that the sample was much younger than past Maine voters and did not accurately reflect the state.
The June 9 primary is hotly contested, although Plattner has faced some backlash over a series of damaging revelations early in the campaign.
Last year, Plattner, an oyster farmer and military veteran, apologized for a series of offensive comments he made in past Reddit posts and covered up a Nazi-related tattoo on his chest – which he said he was unaware of when he got it. Plattner went on a podcast on Thursday to elaborate on his explanation for the tattoo.
But Plattner and his energetic campaign won more union support. He also has the support of Vermont Sen. Bernie Sanders, Connecticut Democratic Sen. Chris Murphy and Dr. Sheldon Whitehouse.
Plattner’s union supporters include the International Association of Machinists and Aerospace Workers. David Sullivan, the union’s general vice president for the Eastern Region, told NBC News he will have a Zoom call with the DSCC to discuss next week’s games. He said his members were upset that Democratic leaders were endorsing Mills after the union endorsed Plattner.
“So I called people in Washington, D.C. and said, ‘Schumer needs to stay out of Maine,'” Sullivan said, adding: “They said they were going to stand their ground and they were going to put millions of dollars into Janet Mills. … We’re going to fight this all the way.”
Gov. Janet Mills is endorsed by the Democratic Senatorial Campaign Committee. (Robert F. Bucati/AP file)
(Robert F. Bucati)
Mills’ campaign has highlighted a host of pro-labor efforts she has supported in recent years, including raising the minimum wage, improving worker safety standards and prohibiting employers from retaliating or discriminating against workers who report violations of labor laws. The Mills campaign also noted that the Maine AFL-CIO would support the bill in 2022, and Monahan issued a statement of support for a bill she vetoed in 2021.
“Governor Mills’ record of fighting for workers’ rights, dignity and wages has earned her praise from many unions in Maine,” Mills spokesman Tommy Garcia said in a statement. “She has made it clear that she will continue to fight for working people in the Senate to lower costs, protect jobs, and improve our economy — and given that she is the only candidate in this race to negotiate and sign legislation that delivers real progress, Maine voters know she will continue to deliver for them.”
The Plattner campaign declined to comment.
Mills had some conflicts with labor groups during his time as governor. In 2019 and 2021, she vetoed labor-backed measures aimed at strengthening the power of third parties to adjudicate in wage, insurance and retirement disputes for public sector workers. The measure remains a top priority for the Maine AFL-CIO.
Mills wrote in his 2021 veto letter that the bill would “delegate fiscal authority to unelected officials regardless of how they are elected.”
Sullivan described labor’s relationship with Mills as “hostile.”
“So Janet Mills is not someone we would support,” he said. “If for some strange reason she ends up miraculously defeating Graham Plattner, you might see a lot of union support for Collins.”
The UAW, which represents about 2,000 workers in Maine, endorsed Plattner the day after Mills launched her campaign in October.
Fein said in an October statement announcing his endorsement of Platner that Platner “focuses on the real issues facing workers across the country, not the distractions used by the billionaire class to divide us. His campaign is rooted in the core issues our union fights for every day: living wages, affordable health care, retirement security and time outside of work to truly live our lives.”
Plattner has also been endorsed by the Maine Chapter of the National Nurses United and the International Federation of Professional and Technical Engineers.
IBEW’s Monahan said in an interview that he was drawn to Plattner’s “impressive” backstory.
“He’s an impressive guy, kind of like [former Sen. Joe] Manchin, [Sen. John] Monahan said he was referring to Democrats from West Virginia and Pennsylvania who stick to the middle of the road and often clash with the party’s base. “The numbers I keep seeing, I mean, it’s not just his polls. This guy really knows how to kick ass.” “
Schumer and the DSCC did not respond to requests for comment. They praised Mills as a strong newcomer when he launched his campaign in October. Mills told NBC News at the time that she had met with Schumer a few months before she launched her campaign, and Schumer encouraged her to run for Senate.
The DSCC has since endorsed Mills’ candidacy and signed a joint fundraising committee agreement with Mills’ campaign to help increase her fundraising. In a memo released last month outlining “multiple paths” to a Senate majority, the DSCC promoted Mills but made no mention of Plattner.
“Janet Mills happens to have such a great record of not only being the only Democrat to win in Maine in 20 years, but she also has a record of fighting for Maine and understanding their issues,” DSCC Chairwoman Kirsten Gillibrand of New York told NBC News in January. “She stood up to President Trump, sued him in court and won. So I think she has the unique courage and ability to actually take on Susan Collins and win. That’s why we support Governor Mills so much.”
Asked whether the Maine Senate race was still winnable if Plattner was nominated, Gillibrand said: “I believe we’re going to have the best nominee and I believe we’re going to win.”
This article originally appeared on NBCNews.com