Sen. Susan Collins, R-Maine, meets with Supreme Court nominee Brett Kavanaugh at her office on Capitol Hill in August 2018. Jose Luis Magana/Associated Press, file

WASHINGTON — Republican Sen. Susan Collins of Maine is facing new attacks from Democrats after a newly surfaced allegation against Supreme Court Justice Brett Kavanaugh put his contentious confirmation back in the public spotlight.

Maine state House Speaker Sara Gideon, her most prominent opponent for reelection next year, posted a photo of Collins and Kavanaugh to Twitter on Sunday with a link to her fundraising page.

“I’m tired of hoping that Susan Collins does the right thing when she has shown time and time again that she puts Donald Trump and Mitch McConnell ahead of Mainers. If you’re with me, please make a contribution to our campaign today,” she wrote.

Collins’ support for Kavanaugh, announced in a 44-minute speech less than a day before the Senate voted to confirm the judge, was a key moment in the high-court saga over allegations of sexual misconduct made by several women who said they had had encounters with him decades ago.

Maine House Speaker Sara Gideon, D-Freeport  Joe Phelan/Kennebec Journal

The fate of Collins, more than any other senator up for reelection next year, is tied to her handling of Kavanaugh, with Democrats arguing that her strong support provided a key boost for his confirmation and undermined her carefully tended moderate profile.

In the speech, Collins called the opposition to Kavanaugh “a caricature of a gutter-level political campaign” and said liberal groups were trying to “whip their followers into a frenzy by spreading misrepresentations and outright falsehoods” about him.

Collins’s stance on Kavanaugh’s behalf, coming just as she entered a reelection cycle, immediately galvanized both her supporters and detractors. She posted the best fundraising quarter of her 23-year Senate career following Kavanaugh’s confirmation – a fact Gideon noted in her introductory campaign video.

“Susan Collins’s vote to put Brett Kavanaugh on the Supreme Court may be paying off for her, but it’s putting women’s control over their own health care decisions in extreme jeopardy,” Gideon said in the video, which also included footage of Senate Majority Leader Mitch McConnell, R-Ky., calling Collins’ handling of Kavanaugh “outstanding.”

“The news stories today are not adding anything to what has already been reported,” said Annie Clark, a spokeswoman for Collins.

Clark said Monday evening that the new allegation is an “accusation that lacks an accuser,” the Associated Press reported.

A Gideon campaign aide said the Democrat has highlighted Collins’s backing of Kavanaugh “consistently since the day we launched.”

The new allegation was first aired in a New York Times Sunday Review article published online Saturday, rooted in the reporting done by two Times reporters for a forthcoming book about Kavanaugh. The piece was later updated to note that the alleged victim did not speak to the reporters and told friends that she did not recall the incident.

Although reporters found only second hand corroboration for the incident, alleged to have taken place at Yale University while Kavanaugh was an undergraduate, it also raised questions about the thoroughness of the FBI and Senate investigations that preceded Kavanaugh’s Oct. 6 confirmation.

Collins at the time called the investigation “very thorough” and reviewed copies of FBI interviews before delivering her climactic speech. Now her opponents are accusing her of relying on a slipshod review of the allegations in determining her vote on Kavanaugh.

Pam Cunningham, a sexual assault survivor affiliated with the Democratic-leaning group Mainers for Accountable Leadership, recalled meeting with Collins ahead of the Kavanaugh vote and receiving assurances from her that the FBI would get to the bottom of the separate allegations from high school acquaintance Christine Blasey Ford and college classmate Deborah Ramirez.

“I asked her, ‘What if the investigation is inconclusive?,’ ” Cunningham said in a statement released by Mainers for Accountable Leadership. “She shook her head and confidently told us, ‘Oh no, it will be a very thorough investigation.’ It wasn’t.”

Republicans, meanwhile, are attacking the Times for reporting an unsubstantiated allegation and Democrats for seizing on it with calls for further investigation and, in some cases, impeachment.

“This shameful attack – aided by a few members of the media – is nothing more than a blatant attempt to undermine the Supreme Court and the will of the people who voted for a conservative judiciary,” said Jess Hunt, a spokesman for the National Republican Senatorial Committee.

Sen. Thom Tillis, R-N.C., a member of the Senate Judiciary Committee who is facing a difficult reelection bid, called the reemergence of the Kavanaugh controversy “an absolute disgrace.”

“Brett Kavanaugh is an outstanding Supreme Court Justice, and the left’s most recent effort to destroy his life and impeach him will fail,” he said.