Troy Jackson looks poised to become Maine’s next Democratic nominee for U.S. Senate after an overwhelming show of political force propelled legions of his followers to become delegates to a nominating convention in Bangor next week.

So many of Jackson’s supporters were chosen at Democratic meetings over the weekend, his would-be opponents saw the writing on the wall. Shenna Bellows and Nirav Shah, perhaps his two most prominent opponents, announced Sunday they would withdraw their candidacies.

Jackson, a former lawmaker and president of the Maine Senate, was received with handshakes and hugs at a meeting of Democrats in York County Sunday, where he mingled with the crowd that had gathered to select that county’s 84 delegates and 17 alternates.

“After yesterday, there’s a good chance the same thing will happen today,” Jackson said in remarks to reporters, referencing his strong showing of support among delegates Saturday.

In York, 83 of the 84 chosen delegates were Jackson supporters, according to his campaign.

As York started voting on delegates, Bellows announced she was dropping out. Shah followed Sunday evening.

Jackson attributed his showing over the weekend to two factors: the strength of his political organizing operation, and his supporters’ conviction in his policy preferences.

He boasted strong support from labor unions both while running in the Democratic primary for governor earlier this year and in his Senate campaign, and said Sunday that his supporters were motivated to see a candidate who backs organized labor and Medicare for All win.

“The last seven or eight days, people just crushed it,” Jackson said. “They were on the phone all the time. I was calling, people were calling to find out where people stood and see if they needed more information about me.”

“This is a real good example of how we really went out and tried to talk to everybody who was going to be a part of this and give them the option of coming our way, and obviously it worked,” he added.

A total of 601 delegates will decide this coming Saturday who the Democratic party’s Senate nominee will be. They will include 101 members of the state party committee and the 500 representatives elected at the county meetings.

While caucuses in some counties were still wrapping up Sunday afternoon, most had elected their delegates. The delegates are not officially pledged to any one candidate, and close to a dozen people are running to replace Platner — though Jackson is the clear favorite with Bellows and Shah out of the running.

Over the weekend, some candidates advertised “slates” of would-be delegates who were pledging to support them in advance of the county meetings, and encouraged their supporters to pick those delegates.

In county after county, Jackson’s campaign pointed to how his delegates dominated.

On social media, Jackson claimed to have secured all 149 delegates in Cumberland County — Maine’s most populous county. Cumberland County is sending almost twice as many delegates to the convention as York, the county with the second highest number. The number of delegates per county is based on turnout in the 2024 primaries.

And he claimed to have swept Penobscot, Kennebec, Knox and Waldo counties, and nearly every delegate in Androscoggin and Hancock counties, bringing his total number of delegates to at least 400 by late Sunday afternoon.

Our Revolution, a political organizing group born out of U.S. Sen. Bernie Sanders’ 2016 presidential campaign, issued a statement on the caucuses referring to Jackson as the “presumptive nominee” and highlighting his campaign.

“This weekend’s overwhelming show of support not only demonstrated the movement’s organizing might, but Maine’s desire to overcome the status quo and center working people,” the group said in a written statement.  

Heading into the weekend, it was unclear how the caucuses would unfold. The process was developed on a tight timeframe after Platner announced July 8 he would be dropping out of the race following an accusation of sexual assault. Platner denied the allegation, but said it would still be damaging to his campaign.

His decision left the Democratic party with less than three weeks to name a replacement, according to parameters set in state law.

The weekend’s county meetings were not without hiccups. In Oxford County, for example, many attendees were upset after a candidate for delegate was apparently left off the ballot. In York County, Kathie Purdy, the chair of the county’s Democratic committee, announced that her name was accidentally included on the ballot when she wasn’t running to be a delegate.

But the verdict from each county appeared clear: Democrats want Jackson to be the new nominee.

Jackson, who is from Allagash in northern Maine, noted Sunday that he and Collins both hail from Aroostook County, an area that has trended more Republican in recent years but where he was still able to win election to the state Senate as recently as 2022.

“People in that area know I’m fighting like hell for everyday working class people, both Republican and Democrat,” he said.

Jackson still has to get through Saturday’s nominating convention in Bangor. In addition to Bellows and Shah, Jordan Wood and Dan Kleban, who were also vying for the nomination, announced Sunday night they would leave the race. A half-dozen candidates remain, including David Costello, a former government official in Maine and Maryland.

Whoever ends up winning on Saturday will have a little over three months to mount a challenge to Republican Sen. Susan Collins in what will be one of the most competitive races for the U.S. Senate nationwide. Collins is widely seen as vulnerable and Democrats are eyeing her seat as a key pickup opportunity. But she’s also a five-time incumbent who has proven her ability to win time and time again.

Jackson said he’ll be focused in the coming week on fundraising. On Saturday, he plans to bring a message of unity to Democrats in Bangor, many of whom are feeling frustrated after the fallout with Platner.

“I want to make sure they know that I understand why they’re upset,” Jackson said. “I do. The issues they care about that Graham talked about are things I have a long track record of fighting for. We can still get those things.”