Maine Democrats are gathering in Bangor to choose a replacement Senate candidate to challenge Republican incumbent Susan Collins after their original nominee, Graham Platner, withdrew. The hurried selection process matters because the race is seen as important to the balance of power in the US Senate, and the party has little time to unite behind a new candidate before the November election.

Platner left the race after an allegation of sexual assault, which he denies. More than 600 delegates are expected to vote in a specially arranged convention, an unusually large replacement process for the state party; former Maine Senate president Troy Jackson is widely expected to win, with Secretary of State Shenna Bellows and former public-health director Nirav Shah also seeking the nomination.