Unions privately urge Chuck Schumer, Democratic leaders to stay out of Maine Senate primary

Union leaders including United Auto Workers President Shawn Fain and International Brotherhood of Electrical Workers' Michael Monahan have recently urged Senate Minority Leader Chuck Schumer and Democratic leaders to withdraw their support for Gov. Janet Mills in Maine's competitive 2026 Senate primary, citing her weaker labor record and arguing that national Democrats should better listen to working-class voters. The intervention highlights a significant rift within the Democratic party as labor unions throw their weight behind Graham Platner, Mills' progressive challenger in the June 9 primary. The UAW, which represents around 2,000 workers in Maine, endorsed Platner the day after Mills launched her campaign in October, while the International Association of Machinists and Aerospace Workers has also joined the effort to boost Platner's candidacy. The unions' private push comes amid polling showing Platner holding a commanding 38-point lead over Mills among likely Democratic primary voters, according to a University of New Hampshire survey from mid-February. The Maine Senate race represents Democrats' best opportunity to flip a Republican-held seat in the 2026 elections, making it a must-win for the party to have any chance of taking over the chamber. Despite this strategic importance, the labor movement's intervention underscores growing discontent with the national Democratic establishment's decision to support Mills, who has had a complicated relationship with organized labor during her time as governor. In 2019 and 2021, Mills vetoed labor-backed measures aimed at strengthening the power of a third party's rulings in disputes over public-sector workers' wages, insurance and retirement—a priority for the Maine AFL-CIO. While Mills' campaign points to her pro-labor efforts including increasing the minimum wage and boosting worker-safety standards, union leaders like David Sullivan of the IAM describe her relationship with labor as "adversarial." Sullivan went as far as suggesting that if Mills somehow wins the primary, unions might support Republican incumbent Sen. Susan Collins in the general election—a remarkable threat given the seat's critical importance to Democrats' Senate majority hopes.