Former Maine Senate President Troy Jackson has all but locked down the Democratic nomination for Senate in Maine after building an overwhelming lead in delegates for next weekend’s convention, prompting several of his competitors to drop out.

Jackson’s supporters won more than 460 of the 500 delegate slots that were up for grabs this weekend across Maine’s 16 counties. They will be among 601 delegates who will meet July 25 to determine the party’s next nominee for Senate after Graham Platner dropped out earlier this month.

The winner will need majority support from the convention, which also includes 101 delegates who automatically come from the Democratic State Committee. Jackson’s success in getting his backers elected delegates means the convention will likely be a formality.

Epidemiologist Nirav Shah ended his campaign Sunday evening and backed Jackson. So did former Capitol Hill staffer Jordan Wood and brewery owner Dan Kleban. Earlier in the day, another opponent, Maine Secretary of State Shenna Bellows, also ended her bid.

“Now it’s time for all of us to come together, build the broadest possible coalition, and defeat Susan Collins,” Jackson said on X after Shah announced his withdrawal. “Let’s get to work.”