Senator Susan Collins Will Not Run for Governor of Maine

ROCKPORT, Me. — After months of open deliberation about her future, Senator Susan Collins of Maine announced Friday that she would not run for governor and would remain in the Senate.

Her decision leaves in place a moderate Republican who is a swing vote; she has stood against President Trump’s agenda more than any other Republican senator and is likely to maintain a role as his foil.

In Maine, her decision, which had been a matter of much public debate here in recent weeks, could open the floodgates for additional candidates to enter an already crowded field in the 2018 election for governor — a race in which Ms. Collins was seen as a heavy favorite though was not assured of winning the primary. Her decision also brings relief to Democrats in this state, who saw Ms. Collins as a popular candidate who appealed to independents and would have made it hard for them to win a governor’s seat that has been in the hands of Republicans since 2011.

“I want to continue to play a key role in advancing policies that strengthen our economy, help our hard-working families, improve our health care system, and bring peace and stability to a violent and troubled world,” Ms. Collins told a packed breakfast meeting here. “And I have concluded that the best way that I can contribute to these priorities is to remain a member of the United States Senate.”

Her decision to stay runs counter to that of a number of other congressional Republicans who, frustrated by Washington’s dysfunction, have announced their retirements. Calling herself an optimist, Ms. Collins declared: “I continue to believe that Congress can, and will, be more productive.” She faces re-election in 2020 if she seeks a fifth Senate term.

Ms. Collins, 64, who was first elected to the Senate in 1996, has become a thorn in the side of Mr. Trump, for whom she did not vote. Most famously, she played a crucial role this summer in dooming his goal of repealing the Affordable Care Act.

“This will be bad news for Donald Trump,” said Stuart Rothenberg, a veteran political analyst for Inside Elections With Nathan L. Gonzales, a nonpartisan newsletter that analyzes campaigns. But, he said, it was good news for those on Capitol Hill “who are looking for dispassionate, pragmatic leadership and for members willing to cross party lines on important votes.”

Since April, Ms. Collins had toyed publicly with the idea of running for governor, which was the first office she ran for, in 1994. Though she lost that race, she said she was still drawn to the ability of a governor to have a direct and immediate effect on people’s lives by creating jobs and spurring economic development.

But she said Friday that what tipped the scales was her seniority — she now ranks 15th out of 100 senators — and that she chairs an appropriations subcommittee where she can steer federal dollars to Maine. Beyond that, she indicated that she liked being able to influence legislative outcomes.

“I feel, as many of my colleagues told me, that I’m often a bridge between the two sides of the aisle and there have been times when I have been able to make a difference,” she told reporters after her announcement. “I like playing that role, and there seem to be fewer and fewer senators who enjoy playing that role.”

Had she run and won the race for governor in 2018, she would have become the first woman in Maine to hold the office.

But while she has been one of the state’s most popular politicians for some time, there was no guarantee that she would win her party’s nomination in the June primary for governor.

Gov. Paul R. LePage, a fellow Republican and ally of Mr. Trump who is barred by term limits from seeking a third term, has been stirring the political pot against her. In the months before Ms. Collins’s announcement, Mr. LePage had tried to galvanize his base against Ms. Collins and discourage her from entering the race. Gov. LePage was traveling in Iceland on Friday, and his press secretary, Julie Rabinowitz, declined to respond to a request for comment.

Ms. Collins, who has glided to victory in her recent elections, this time faced the prospect of bruising and expensive attacks from the right. Far from being able to clear the field of competition, she would have entered a campaign free-for-all with at least 18 others so far — four Republicans, 10 Democrats and four third-party candidates.

“She hasn’t had a competitive election for a very long time, and so there’s much more uncertainty for her now than in previous elections,” said Amy Fried, a political scientist at the University of Maine. Ms. Fried predicted that Ms. Collins would have faced stronger attacks “in a way she just hasn’t had from her own party.”

Mary Mayhew, Mr. LePage’s former health and human services commissioner, who has cast herself in the LePage mold, may be the most immediate beneficiary of Ms. Collins’s decision.

“Her announcement today allows many individuals who may have been waiting to now jump on board my campaign,” Ms. Mayhew said in an interview.

Asked whether criticisms of her, particularly by Mr. LePage, had influenced her decision, Ms. Collins said no. “It really didn’t bother me,” she said, adding that she was confident she could have prevailed in the primary and in the election.

Ms. Collins made her announcement at a breakfast meeting of the Penobscot Bay Regional Chamber of Commerce. She drew an audience of about 225 people — far more than the typical chamber breakfast, officials said — and kept them in suspense for more than half an hour as she delved into her reasons for opposing the repeal of the Affordable Care Act.

Finally, she turned to what she called “the elephant in the room.” She said a Senate colleague, whom she did not identify, had written her a note urging her to stay in the Senate. Ms. Collins read the note out loud: “The institution would suffer in your absence. While the temptation might be to walk away and leave the problems to others, there are very few who have the ability to bring about positive change. You are such a person.”

Once she made it clear that she was staying put, the audience broke into applause.

“I called her office to say please stay, we need you desperately in the Senate,” said Barbara Kent Lawrence, an author who attended the breakfast and said she was a Democrat. She said Ms. Collins was fair, rational and civilized, and while those would be good qualities in a governor, “she is more powerful where she is.”

“The country needs her more than Maine does now,” Ms. Lawrence said. “We’re in a lot of trouble because we’ve stopped listening to each other.”