Washington — Maine Democrats are gathering Saturday for the party’s nominating convention to select a U.S. Senate nominee to replace Graham Platner on the ballot in November, with former state Senate President Troy Jackson poised to secure the nomination.

Around a dozen Democrats planned to seek the nomination earlier this month, after Platner dropped out of the race in the wake of a sexual assault allegation. 

But the field narrowed last weekend after Maine counties held nomination meetings to select delegates, and Jackson succeeded in getting most of his slates of delegates elected. The vast majority of the 500 delegates elected are backing Jackson.

Jackson effectively locked up the nomination, having informally secured a majority of the delegate slots that will determine the nominee. 

The outcome led the race’s other prominent candidates — like Maine Secretary of State Shenna Bellows and former director of the Maine Center for Disease Control and Prevention Nirav Shah — to bow out. They encouraged the party to come together to defeat Republican Sen. Susan Collins. 

But lesser-known candidates David Costello and Saundra Pelletier are still set to appear on the convention ballot Saturday. Maine Beer Company co-founder Dan Kleban also qualified to appear on the ballot, but said he’s endorsing Jackson and submitted a request to withdraw.

“We look forward to hearing directly from these candidates and bringing Democrats from every corner of Maine together on Saturday to choose the strongest nominee to defeat Susan Collins,” Maine Democratic Party Executive Director Devon Murphy-Anderson said in a statement.

At the nominating convention, delegates from Maine’s 16 counties will cast their votes. And while the delegates on Jackson’s slate aren’t legally bound to support him, they’re widely expected to do so.

What to know about Troy Jackson

Jackson, 58 and a fifth-generation logger, was state Senate president from 2018 to 2024, and previously served as a state representative in Maine’s northernmost region. He used to be a Republican and in his first state House race ran as a Republican. Jackson was first elected to the state House as an independent in 2002, but then became a Democrat. 

Before entering the race for U.S. Senate, he ran for governor and was backed by Platner and independent Sen. Bernie Sanders of Vermont. Jackson finished third in the gubernatorial primary in June.

He’s generally aligned with Sanders, having also worked on his 2016 presidential campaign, and he supports progressive policies.

Platner’s departure from the Senate race triggered an abbreviated process to find a replacement. After winning the nomination in June, Maine election law stated that a nominee must withdraw by 5 p.m. on the second Monday in July in order to be replaced on the ballot, at which point the party has two weeks to select a new nominee. 

Maine Democrats pursued the nominating convention to select a candidate with input from Mainers, and scheduled it just before the July 27 deadline.