WASHINGTON — President Trump’s bid to confirm Judge Brett M. Kavanaugh to the Supreme Court was thrown into uncertainty on Sunday as a woman came forward with explosive allegations that Mr. Kavanaugh sexually assaulted her when they were teenagers more than three decades ago.
The woman, Christine Blasey Ford, 51, a research psychologist at Palo Alto University in Northern California, said in an interview with The Washington Post that during a high school party in the early 1980s, a drunken Mr. Kavanaugh pinned her on a bed, groped her and covered her mouth to keep her from screaming.
“I thought he might inadvertently kill me,” the newspaper quoted her as saying. “He was trying to attack me and remove my clothing.”
Judge Kavanaugh has denied the accusations, and in a terse statement on Sunday, the White House said it stood by those denials. It signaled that it had no intention of pulling the nomination.
But Ms. Ford’s decision to put her name behind accusations that began to circulate late last week — a choice made after weeks of reluctance — appeared to open a door to a delay in a Senate committee vote on the nomination scheduled for Thursday. The disclosure also injected a volatile #MeToo element into the confirmation debate, one that is playing out in the overwhelmingly male Republican-led Senate during a midterm election that has energized Democratic women.
One Republican on the Senate Judiciary Committee, Jeff Flake of Arizona, told Politico that he was “not comfortable voting yes” on the nomination until he learned more about Ms. Ford’s account. A single Republican objection on the committee, which has 11 Republicans and 10 Democrats, could force a delay.
Another Republican on the panel, Lindsey Graham of South Carolina, said on Twitter that “if Ms. Ford wishes to provide information to the committee, I would gladly listen to what she has to say and compare that against all other information we have received about Judge Kavanaugh.” But he said he hoped to keep the process on schedule. Senator Bob Corker, Republican of Tennessee, made a similar statement to Politico.
Ms. Ford’s account comes as Democrats are already raising questions about Judge Kavanaugh’s truthfulness during his confirmation hearings this month. They have accused him of dissembling on a range of issues from his time in the George W. Bush White House, including a breach of secret Democratic files on judicial nominations and discussions about detainee policy and torture.
The new revelation prompted a hurried effort by Senator Charles E. Grassley of Iowa, the Judiciary Committee chairman, to set up conference calls to allow Democratic and Republican aides to interview both Judge Kavanaugh and Ms. Ford before Thursday’s scheduled committee vote. A spokesman, Garrett Ventry, said it was routine to hold such calls “when updates are made to nominees’ background files.”
The decision about any delay in the vote could rest on the opinions of two Republican women: Senators Lisa Murkowski of Alaska and Susan Collins of Maine. Both are publicly undecided about Judge Kavanaugh.
Ms. Collins said in an interview on Sunday night that she considered the allegations seriously and that Ms. Ford needed to be personally interviewed to get a fuller account. But Ms. Collins, who could conceivably decide the outcome in the narrowly divided Senate, said Democrats had done a disservice to both Ms. Ford and Judge Kavanaugh with their handling of the accusations.
“What is puzzling to me is the Democrats, by not bringing this out earlier, after having had this information for more than six weeks, have managed to cast a cloud of doubt on both the professor and the judge,” she said. “If they believed Professor Ford, why didn’t they surface this information earlier so that he could be questioned about it? And if they didn’t believe her and chose to withhold the information, why did they decide at the 11th hour to release it? It is really not fair to either of them the way it is was handled.”
The White House, which has taken great pains to portray Judge Kavanaugh as a champion of women, sought to bolster him by pointing to statements by women who have known him and testified to his character. Those included a letter from 65 women who said that they knew him in high school and that he had “always treated women with decency and respect.”
Advisers to Mr. Trump were trying to avoid publicly assailing the accuser while hoping that the lack of contemporaneous corroboration for Ms. Ford’s account would mean that Senate Republicans could move ahead without addressing it in detail.
More delicately, advisers were privately urging Mr. Trump, who has been accused of sexual harassment by more than a dozen women, not to speak out about the allegations against Judge Kavanaugh on Twitter for fear that he would only inflame the situation.