Trader consensus heavily favors Graham Platner at 90.5% implied probability to win Maine's June 9 Democratic U.S. Senate primary, driven by the Emerson College poll from March 21-23 showing him at 55% to Gov. Janet Mills' 28% among likely voters, with broad leads across Democrats, independents, genders, and age groups. The combat veteran and oyster farmer's outsider appeal to working-class Mainers has sustained momentum despite Mills' attacks highlighting his decade-old Reddit posts on atheism and other topics, which have not dented recent polling averages like DDHQ's 52%-33% Platner edge. Other candidates trail far behind amid a crowded field. While ranked-choice voting could play a role, late-breaking scandals gaining traction, a Mills fundraising surge, or undecided voter shifts toward the establishment governor represent realistic upset paths before ballots drop.