In an election shaped by the #MeToo movement, where female candidates and voters are likely to drive any Democratic gains, Mr. Clinton finds his legacy tarnished by what some in the party see as his inability to reckon with his sexual indiscretions as president with a White House intern, Monica Lewinsky, as well as with past allegations of sexual assault. (Mr. Clinton has denied those allegations.) Younger and more liberal voters find little appeal in Mr. Clinton’s reputation for ideological centrism on issues like financial regulation and crime.

“I’m not sure that with all the issues he has, he could really be that helpful to the candidates,” said Tamika D. Mallory, an organizer of the Women’s March, who’s now promoting female candidates across the country. “It would do the Democratic Party well to have Bill Clinton focus on his humanitarian efforts.”

Rebecca Kirszner Katz, a veteran Democratic strategist, says many Democrats have reassessed the party’s support for Clinton’s behavior in light of changing views about women, power and sexual misconduct.

“It was an abuse of power that shouldn’t have happened and if the Clintons can’t accept that fact 20 years later, it’s hard to see how they can be part of the future of the Democratic Party,” said Ms. Katz, who worked as a top strategist on Cynthia Nixon’s bid to unseat Gov. Andrew Cuomo of New York this year.

Mr. Clinton, 72, currently chairs the board of the Clinton Foundation, helping to promote and manage the philanthropic organization he founded after leaving the White House. Angel Ureña, a spokesman for Mr. Clinton, said the former president believes “this election should be about these times and these candidates.”

“President Clinton is encouraged by the large number of impressive Democrats running for office who are personally telling their stories and laying out their vision for how to get America back on track,” he said. “They are the people voters need to hear from.”