Democratic prospects of holding a US Senate seat in Maine have risen sharply after fresh sexual misconduct allegations against the party's nominee, Graham Platner, prompted speculation that he will quit the race. Platner has denied his ex-girlfriend Jenny Racicot's allegation of nonconsensual sex, reported by Politico, but has admitted he is considering standing down, and prominent backer Bernie Sanders has now urged him to step aside. The turmoil matters because it has reshaped the contest against Republican incumbent Susan Collins and left the Maine Democratic Party scrambling to line up a replacement.

According to Kalshi's betting markets, the odds shifted from a near-even split on 2 July — 50 per cent for Collins against 49.7 per cent for the Democratic challenger — to a 59 per cent chance of a Democratic win by the Tuesday after the allegations surfaced. The party faces two tight deadlines: Platner must leave the race by 13 July if he intends to, and a replacement must be chosen by 27 July. Sanders, one of Platner's most vocal supporters, said he had spoken to the candidate about "the best path forward for Maine" and recommended he step down in light of the "very serious allegations".