If Graham Platner withdraws from the Senate race in Maine, the task of finding a new Democratic nominee will fall in part to Charles F. Dingman, a progressive with a soft-spoken, professorial style who is chair of the Maine Democratic Party.
Mr. Dingman, 72, a lawyer from rural Leeds, Maine, who enjoys hiking mountains — sometimes two a day — has been in his role for about a year and a half.
But now, with Mr. Platner’s campaign upended by a rape allegation that he denies, Mr. Dingman’s position has taken on a new urgency.
Mr. Platner, who has quickly bled support from his most important backers, has suggested he is considering leaving the race. If he were to do so, Mr. Dingman would preside over the process of finding a new candidate to run against the vulnerable incumbent Republican, Senator Susan Collins, in a race that will help determine control of the Senate.
Mr. Platner has until July 13 to withdraw, a deadline dictated by state law. The state party would then have until July 27 to name a new nominee. It is uncharted territory: There is no set process by which the party must choose a replacement.
Mr. Dingman has already played a central role in the Democratic pressure campaign to push Mr. Platner out of the race, leading a statement urging Mr. Platner to go, hours after a Politico report on Monday that described the sexual assault allegation. Mr. Dingman was on vacation when the news broke and was driving back to Maine on Tuesday, said Kathie Purdy, the chairwoman of the York County Democrats.
The executive director of the Maine Democratic Party, Devon Murphy-Anderson, said in a video posted on social media late Tuesday that the party was working “around the clock” to develop an open and fair process to replace Mr. Platner. “Unfortunately, Graham Platner’s team has repeatedly reached out to us in an attempt to put their thumb on the scale of what this process looks like,” she said. “We have repeatedly reiterated to Graham Platner’s team that they have no role in determining our next Democratic nominee.”
There has been talk of a statewide convention or some form of caucuses to pick a candidate. Tony Buxton, a former Maine Democratic Party chair, suggested Mr. Dingman could perhaps simply pick a candidate unilaterally if Mr. Platner quit, though that was not expected.
Mr. Buxton, who worked at a law firm with Mr. Dingman for decades, described him as “very liberal” and “very dedicated to high principles.”
“He’s not a traditional Democratic state chairman,” Mr. Buxton said. “He’s not a politician.”
Mr. Buxton predicted that Mr. Dingman would be “very intent on respecting the constituency” that elevated Mr. Platner in the primary. He also said he expected Mr. Dingman would take a consensus-based approach to finding a nominee.
“He’s a low-key consensus builder,” David Farmer, a Democratic strategist, said of Mr. Dingman, describing him as a “cool headed” and kind.
“Given the circumstances, it’s going to be hard to make everybody happy,” added Mr. Farmer, who worked closely for years with Mr. Dingman on a push related to state health care in the State Legislature. “He will lean toward making a process that is transparent and inclusive.”
Mr. Dingman grew up on a farm in Turner, Maine, and has lived in Leeds since the 1970s, moving there shortly after graduating from Columbia Law School. He received his undergraduate degree from Bowdoin College in Maine. He has worked as a lawyer in state government posts and now practices at the firm Kozak & Gayer, where he focuses on health care law.
He did not immediately respond to a request for comment Tuesday.
Mr. Dingman was a delegate for Senator Bernie Sanders, the progressive Vermont independent, in the 2016 and 2020 presidential elections. As Mr. Dingman rose to party chair last year, he told The Maine Morning Star that he wanted the state party to “be understood to be the party of Maine’s working people.”
The party, Mr. Dingman told the news outlet, needed to reach “working people who may feel disillusioned, who may feel frustration with conditions of their lives that haven’t been adequately addressed.”
BJ McCollister, a Democratic National Committee representative, said few Mainers had “done as much as Charlie has done to make sure that there is some sort of social safety net protection — and the type of protections that progressives are often fighting for.”
Still, Mr. McCollister said Mr. Dingman had worked hard to be a “big-tent party” chair over the last year.
“He’s not one of those party chairs that are going to throw heavy elbows and try to be a party boss type,” Mr. McCollister said.
Mr. Buxton, the former chair, said among Mr. Dingman’s most salient traits is his lawyerly precision. Once, while cross-examining a state employee who had led a contract that was facing scrutiny, Mr. Dingman made the employee look so unprepared that the staff of the Republican governor at the time, Paul LePage, fired the employee.
“On the spot,” Mr. Buxton said. “He walked out of the room and was fired.”
