Maine Democrats would have less than three weeks to find a new candidate to take on the nation’s most formidable blue-state Republican in one of their party’s most important midterms contests.

With the party’s current nominee, Graham Platner, seeking to navigate an exit from the race as soon as Wednesday in the face of heavy intraparty pressure, people familiar with the matter told CNN, a field of prospective candidates is quickly emerging to take on five-term GOP Sen. Susan Collins.

The behind-the-scenes scramble is being closely watched by Democrats in Washington, who see Maine as a critical seat in their effort to flip the Senate this November. But so far there’s no consensus pick, and anxiety is mounting inside the Democratic Party about how to elevate a top-tier nominee after Platner’s high-profile meltdown just 100 days from the election.

Three of the possible contenders — Nirav Shah, Troy Jackson and Shenna Bellows — are eyeing the Senate race fresh off their own failed gubernatorial bids. Jackson, a former state senator, and Bellows, the current Maine secretary of state, have described themselves as progressive populists, while Shah, a former high-ranking state and federal health official, is considered more moderate, with possible bipartisan appeal.