Former vice president Joe Biden is under increasing pressure from women’s rights groups, prominent African American leaders and other supporters of Anita Hill to acknowledge his personal responsibility for his handling of the 1991 confirmation hearing of Supreme Court Justice Clarence Thomas.

As Biden inches toward a 2020 presidential run in which female and black voters will play an outsize role, some are urging him to extend a personal apology to Hill, something he is not believed to have done in the nearly 30 years since the hearing took place. Others are calling for him to publicly demonstrate that he understands he made mistakes at the time as chairman of the Senate Judiciary Committee.

But few are satisfied with his remarks about Hill at an event in New York on Tuesday night, at which he said he still regretted he “couldn’t come up with a way to get her the kind of hearing she deserved.”

“He hasn’t accepted the ownership of the fact that he was the most powerful person in the role and in the room at that time,” said Toni Van Pelt, president of the National Organization for Women. “I think that he has a hard time because he doesn’t really completely understand yet. He is still protecting his gender.”

“I think he needs to have a conversation with Ms. Hill,” Van Pelt added.

Bill Russo, a spokesman for Biden, declined to comment when asked whether the former vice president has contacted Hill to apologize or plans to do so in the future. Hill did not respond to requests for comment.

Hill, who is black, faced accusatory and deeply skeptical questioning from the all-white, all-male Judiciary Committee when she testified that Thomas had repeatedly made unwanted sexual advances toward her as her supervisor at the Education Department and the Equal Employment Opportunity Commission. Thomas denied the allegations.

Anita Hill spoke to the Post in November 2017 to reflect on her 1991 testimony about sexual harassment, the slow pace of change and the #MeToo movement. (The Washington Post)

Beyond the questioning, critics of Biden have cited his refusal as chairman to allow testimony from sexual harassment experts and additional witnesses who could have supported Hill’s account.

Biden on Tuesday touched on the racial and gender dynamics of the hearing, lamenting that Hill faced “a bunch of white guys” on the panel.

Kelly Dittmar, assistant professor of political science at Rutgers University-Camden and a scholar at the Center for American Women and Politics, said it was particularly ironic that Biden made his remarks Tuesday night at the “Biden Courage Awards,” an event honoring those who have worked to combat sexual assault on college campuses.

“He said at one point, ‘If you see this happening and you stand by, you’re a coward,’ ” Dittmar said. “But the biggest critique of his behavior in the hearings was that the men in the room were treating Anita Hill with a high level of disrespect and scrutiny that I think many feel was undeserved and unfair, and he didn’t step in in the way people would have hoped.”

She added that Biden’s slow acknowledgment of his own role in the hearing “only perpetuates some of that frustration” among those defenders of Hill who have been angry since 1991.

“It’s not to villainize Joe Biden. I actually think it’s an opportunity in this moment — especially as somebody who talks about bystanders — for him to say, ‘I was actually a bystander,’ ” Dittmar said.

During Biden’s last White House bid, in 2008, his handling of the Thomas hearing did not come under significant scrutiny, in part because his campaign failed early on. His first White House bid, in 1988, took place years before the Thomas hearing. The 2020 campaign looms as the first of the #MeToo era, which has heightened Democratic voters’ expectations of their candidates.

Last fall’s confirmation hearing for Supreme Court Justice Brett M. Kavanaugh, during which Christine Blasey Ford testified that Kavanaugh had sexually assaulted her decades ago, brought renewed attention to the way the Senate Judiciary Committee handles such accusations.

“Saying ‘I wish I could have done something’ just doesn’t seem to fit with the history and the facts and what happened,” Christina Reynolds, a spokeswoman for Emily’s List, said of Biden. “It implies that he couldn’t have done anything else, and it implies that the only thing wrong was she faced a bunch of white men asking inappropriate questions — and that wasn’t the only problem with that hearing.”

The organization, which backs Democratic women who support abortion rights, has not yet endorsed a candidate in the presidential primary.

Reynolds said it was up to Hill to decide whether Biden should offer a personal apology, and that ultimately women’s rights advocates were hoping to hear the former vice president give an accounting of his own actions and their impact.

“We’re not here to dictate how an apology works,” she said. “What we’re most concerned about is, how do we make sure things like that don’t happen again?”

African American political leaders are also calling for Biden to go further to repair damage from more than two decades ago.

In an interview, the Rev. Al Sharpton said he had been encouraged to hear Biden admit mistakes in his handling of the Hill testimony, just as Biden had expressed regret for elements of the 1994 crime bill which critics say led to mass incarceration of black men. Hill’s many defenders, he said, need to hear more.

“I think Joe’s sticking his toe in the bathwater,” Sharpton said. “Whether he’ll stick the rest of his body in and open up, we’ll see. But he’s got to address it. People feel that she was disregarded, disrespected. In many ways it’s just as much about how it was done, as what was done to her.”

Former Georgia gubernatorial nominee Stacey Abrams (D), who is mulling a 2020 bid of her own, on Wednesday called Biden “a lovely man who’s done a great deal for our country” — but said he has more work to do on the issue.

“Whether we think he has taken sufficient responsibility will be determined as the process continues, but I think he’s begun the process appropriately by saying, ‘I know there’s pain, and I want to respond to that pain,’ ” Abrams said on ABC’s “The View.”

Some of Biden’s defenders have argued that voters should focus on the entirety of Biden’s record. Ron Klain, who was chief counsel of the Judiciary Committee in 1991 and was Biden’s chief of staff from 2009 to 2011, said on MSNBC Wednesday that some voters may never forgive Biden for his handling of the Thomas hearing. He urged Democrats to consider Biden’s work on women’s rights, including his spearheading of the Violence Against Women Act.

In an interview last year with Elle magazine, Hill was asked about Biden’s statement the previous year that he owed her an apology. She responded that the topic had “become sort of a running joke in the household when someone rings the doorbell and we’re not expecting company.”

“ ‘Oh,’ we say, ‘is that Joe Biden coming to apologize?’ ” she told the magazine.

Asked then whether she was still waiting for Biden to reach out to her, Hill, now a Brandeis University professor, said she has moved on.

“There are more important things to me now than hearing an apology from Joe Biden. I’m okay with where I am,” she told Elle.

David Weigel and John Wagner contributed to this report.