Three Democrats considering bids to replace Graham Platner in Maine's U.S. Senate race are running essentially even with Republican Sen. Susan Collins in a new poll released as party leaders race to choose a nominee before a July 27 deadline.

Each of the three polled matchups fell inside the margin of error, leaving one of the most contested seats on the 2026 Senate map looking wide open.

The Z to A Research poll, first reported by NOTUS, tested Collins against former Maine Center for Disease Control and Prevention Director Nirav Shah, Maine Secretary of State Shenna Bellows, and former state Senate President Troy Jackson.

Shah led Collins 47% to 46%. Bellows and Collins tied at 47%. Jackson trailed 48% to 47%.

The survey of 988 likely Maine voters has a margin of error of plus or minus 3.12 percentage points, according to the pollster's memo, which said the poll was commissioned by a pro-Shah outside group. Fieldwork ran July 7-8, wrapping up just before Platner formally announced he was suspending his campaign.

Platner's collapse drives the timing.

The Sullivan oyster farmer, whose insurgent bid had drawn national progressive backing, said Wednesday he would withdraw after a Politico story detailed a sexual assault allegation from a former girlfriend, Jenny Racicot.

Platner has called the accusation "categorically false."

The Democratic Senatorial Campaign Committee said it would not spend on the race with him on the ballot. And top allies, including Sens. Bernie Sanders, I-Vt., and Elizabeth Warren, D-Mass., pulled their endorsements.

The poll captured the fallout in real time.

Just 21% of Maine voters viewed Platner favorably, the memo said, and NOTUS reported that 72% viewed him unfavorably, with nearly two-thirds saying he should exit the race.

Platner's own campaign ran an internal flash poll testing the same three replacements, NOTUS reported, citing Politico. That survey put Jackson ahead of Collins 49% to 44% and showed Bellows and Shah essentially tied with the incumbent.

The Z to A poll did not test other Democrats who have entered or signaled interest, including Maine Beer Company co-founder Dan Kleban and former congressional staffer Jordan Wood.

Maine Democrats voted Wednesday to hold a nominating convention of 600 delegates to select Platner's replacement.

Under state law, Platner must file withdrawal paperwork by 5 p.m. Monday for the party to name a new nominee by July 27.

Collins, seeking a sixth term, is the only Senate Republican defending a state President Donald Trump did not carry in 2024, making Maine central to Democrat hopes of flipping the chamber.