Ms. Hill said there was not “any evidence” of that. But if it is true, she said, there is a possible explanation: “They saw a flawed process where they weren’t going to be heard and they might end up being destroyed.”

With Mr. Biden almost an instant front-runner in a very crowded Democratic field, the subject of Anita Hill is a delicate one among Democrats — even those who believe Mr. Biden bungled the hearings. Many former Judiciary Committee aides and other people who participated did not want to talk on the record because they feared that scrutiny of Mr. Biden’s past conduct would undermine the campaign of the candidate some think could be best positioned to defeat President Trump, whose treatment of women is a huge issue for Democrats.

“It’s definitely going to come up,” Representative Jan Schakowsky, Democrat of Illinois, said in an interview this week. “I don’t know how exactly he is going to handle it, but there will be scrutiny of the Anita Hill issue, which I think resonates in a different way today. So he has to be able to respond to it in the context now of the #MeToo movement.”

Representative Jamie Raskin, Democrat of Maryland, was even more pointed. “Biden’s chairmanship of the Judiciary Committee during the Thomas nomination reflected his sense of institutionalism a lot more than any sense of feminism. None of this would be disqualifying, but it does not stand up well to the feminist sensibilities of the #MeToo era.”

Some of Mr. Biden’s former colleagues who served with him said that while he might have erred in the Thomas hearings, his full record needs to be considered rather than only one element of a lengthy career in politics.

“I think anybody who has been in public life for as long as he was in public life and has gone through changing times is going to have to respond to those moments in history when they wish they had done it a little differently,” said Barbara Boxer, a former Democratic senator from California. “I think Joe has evolved on all the issues that are going to come up, among them the Anita Hill hearings.”

Some say Mr. Biden was more sensitive to the fact that Justice Thomas was African-American than to issues of gender; others say he was loath to investigate Ms. Hill’s accusations in part because he wanted the confirmation hearings to focus on legal issues, not personal ones.