Maine Senate race echoes Collins’ 2020 upset bid

Maine’s 2026 Senate race is shaping up as a warning shot for both parties, because it looks like Susan Collins’s 2020 upset bid without being a carbon copy. Collins, first elected in 1997 and now seeking a sixth term, will face voters in the general election on November 3 after a Democratic primary on June 9, in a contest that could help decide Senate control.

The comparison to 2020 is hard to ignore. Collins defeated Democrat Sara Gideon 51.0% to 42.4% after trailing in nearly every public poll, and that race became the most expensive in Maine history. Collins spent about $23 million; Gideon spent nearly $48 million. That result still hangs over the state as Collins again enters a race marked by early signs of vulnerability and by the same basic challenge for Democrats, whether to turn Maine into a referendum on an entrenched Republican or watch her survive another national wave.

The mechanics matter as much as the history. Maine uses ranked-choice voting for state-level primaries and for federal general elections, and the system was first used in a Maine primary on June 12, 2018. In a state that has repeatedly split its presidential and Senate behavior, ranked-choice voting can reward broad coalitions and punish fragmented opposition, especially if the field remains divided into competing wings.

That divide is already visible. Senate Minority Leader Chuck Schumer and the Democratic Senatorial Campaign Committee have backed Gov. Janet Mills, a 78-year-old moderate in her second term. Graham Platner, a veteran and oyster farmer with no prior elected office, has drawn backing from Bernie Sanders, Martin Heinrich, Ruben Gallego and Elizabeth Warren. Platner’s campaign has also faced scrutiny over past controversial comments and a tattoo resembling a Nazi symbol, which has complicated the party’s effort to present a unified challenge to Collins.

Republicans, meanwhile, are treating Collins as one of their most important defenses in a 53-45 Senate. She has endorsements from John Thune and Tim Scott’s NRSC, but Donald Trump has given mixed signals and has not formally endorsed her. The race is rated competitive by Cook Political Report, Inside Elections and Sabato’s Crystal Ball, a reminder that Maine is not just replaying 2020. It is testing whether Collins’s independence brand, Democratic coalition math and the state’s ranked-choice system can combine to produce a familiar result under very different conditions.