Troy Jackson, a progressive, has built a clear edge in Maine’s abbreviated nomination process to replace Graham Platner as the Democratic Senate nominee after he dropped out this month under pressure from party leaders.
On Sunday, as Mr. Jackson widened his considerable advantage among a group of delegates who will pick the nominee, another candidate, Shenna Bellows, dropped out of the race.
Mr. Jackson, a former president of the Maine State Senate, appeared to have the support of a broad group of delegates elected at county meetings this weekend for a statewide convention next week. At the convention, the delegates will vote on a replacement for Mr. Platner, who ended his campaign after a rape accusation that he has denied.
The Democratic nominee who emerges from that convention will face Senator Susan Collins, a vulnerable fifth-term Republican incumbent, in the November midterm election. The race in Maine is considered central to Democrats’ chances of winning back the Senate.
By Sunday, an analysis of county results showed more than half the number of delegates who will be invited to attend the convention were listed as supporting Mr. Jackson in a slate of delegates released by his campaign. Mr. Jackson’s momentum during the weekend was also clear in interviews with candidates, voters, delegates and party operatives. To win at the convention, a candidate will need the support of a majority of the 601 delegates, who will come from Maine’s 16 counties and a state Democratic committee.
Although Mr. Jackson emerged a clear frontrunner, and some delegates have described their preferences in their nominating documents, they could still change their minds before the convention. Other variables, including a high-profile debate this week, could still shift the race.
The leading candidates to replace Mr. Platner have been broadly aligned on politics. At a debate last week, they disagreed on little beyond daylight saving time.
But Mr. Jackson, a fifth-generation logger from northern Maine, had been seen as perhaps the most closely aligned ideologically with Mr. Platner, who ran on a progressive, populist message before his campaign imploded this month. Mr. Jackson has significant union support and talks often of “solidarity.” Like Mr. Platner, he supports universal health care and accuses Israel of carrying out a genocide in Gaza. And he had joined Mr. Platner on the campaign trail.
Mr. Jackson ran for governor last month, finishing third. Ms. Bellows, the Maine secretary of state, finished fourth in that race, while Dr. Nirav Shah, a former public health official, finished second. All three entered the race for Senate this month.
Ms. Bellows said in a statement on Sunday that “the best way that I can serve our state and country at this moment is by focusing” on her role as Maine’s secretary of state.
“The most important thing we can do in this moment is unite to defeat Susan Collins,” Ms. Bellows wrote on social media, adding in her statement that “Democrats don’t have a day to waste.” She did not immediately endorse another candidate.
Her bid ended 11 days after Mr. Platner suspended his campaign. Ms. Bellows ran against Ms. Collins in 2014 and lost by 37 percentage points. Democrats in Maine have spent the weekend gathering at county meetings where they have been selecting 500 delegates who will join about 100 members of a state party committee in voting at the convention, which is set to be held in Bangor.
On Sunday, in a gusty parking lot outside a performing arts center, Mr. Jackson gave a speech to his supporters before the York County delegate vote kicked off.
“Yesterday, we showed them what this movement can do, what your movement can do,” he said. “Today, York County gets that chance. Let’s elect this slate, let’s win this nomination, and let’s unite this party.”
Further north, in coastal Hancock County, Mr. Platner’s home county, all but one of the 23 delegates chosen Saturday appeared to be supporters of Mr. Jackson, according to Marcia Myers, chair of the Hancock County Democrats.
“Nobody is committed — officially committed,” Ms. Myers said, but she added that Mr. Jackson’s success apparently stemmed from a mix of strong organization and a sense among Mr. Platner’s supporters that Mr. Jackson was the closest politically to the former nominee. “His supporters have seemed pretty closely aligned with Troy from early on, even before Graham dropped out.”
On Sunday, Mr. Jackson moved to secure the support of Mainers who had backed Ms. Bellows, as he thanked her on social media for her “friendship,” her “service” and her “dedication to our shared values.”
“Defeating Susan Collins will take all of us,” he added, “and I’m grateful for your commitment to bringing Democrats together around that mission.”
Another candidate, Jordan Wood, who lost in a competitive House primary last month, also responded swiftly to Ms. Bellows’s exit, saying on social media that he was inspired by her. “Proud to call you a friend,” he wrote.
The candidates piled into the unusual race after Mr. Platner’s exit and have built candidates on the fly.
In a debate last week, Ms. Bellows acknowledged that she was rushing to study up on Ms. Collins’s recent voting record. When a debate moderator corrected her about Ms. Collins’s position on U.S. military action in Venezuela, Ms. Bellows said, “Forgive me — a week ago I was on vacation.”
