The Democratic primary will be held on June 9, 2026. The winner will be determined by ranked-choice voting. Only Mills, Platner and 2024 nominee David Costello qualified for the ballot. The market resolves to whichever candidate receives the most votes after ranked-choice tabulation is complete. Results will be available from the Maine Secretary of State.

Background

This is the Democratic primary for Maine's U.S. Senate seat. Janet Mills is the 75th governor of Maine, having been re-elected with 55.69% of the vote in 2022. Graham Platner is an oyster farmer, harbormaster, and military veteran who has been characterized as a populist and a progressive who is critical of the Democratic Party establishment. Polling has found Platner with a consistent lead over both Mills in the primary and Collins in the general election. Senate Minority Leader Chuck Schumer backs Mills, while a second U.S. senator endorses Platner in the race to take on Sen. Susan Collins.

Considerations

The race pits a centrist sitting governor against a progressive firebrand in a generational contest, with the 78-year-old Mills pointing to her track record of winning statewide while 41-year-old Platner casts himself as an outsider candidate. One candidate terminated her campaign and endorsed Mills after Platner's previous comments appearing to minimize the issue of sexual assault in the military. Platner has faced scrutiny after it was revealed that he had a tattoo that resembled a Nazi symbol, which he says he has since covered up.

This description was generated by AI.