Joseph R. Biden was supposed to be congressional Democrats’ best friend this year, helping down-ticket candidates win races with his crossover appeal.
Instead, Republicans say the presumed Democratic presidential nominee is becoming a huge liability as Republican candidates and groups move quickly to weaponize a decades-old sexual assault allegation against the former senator and vice president.
“It’s odd that Democrats who were once so outspoken about ‘believing survivors’ have gone silent,” said Bob Salera, spokesman for the National Republican Congressional Committee, the campaign arm for House Republicans. “They’re going to have to answer what’s changed other than the accused sexual predator being their presidential candidate.”
Democrats across the country are facing uncomfortable questions about party leaders’ refusals to acknowledge Mr. Biden’s growing #MeToo problem.
Mr. Biden outlasted a crowded field of candidates despite complaints from a series of women who said the former vice president’s touchy-feely behavior creeped them out.
One of those women is Tara Reade, who once worked for Mr. Biden as a Senate staffer. In her case, Ms. Reade says, Mr. Biden’s unwanted physical contact crossed the line into sexual assault.
She said Mr. Biden in 1993 pinned her to a wall in the Capitol, put his hand under her skirt and violated her with his fingers.
The accusation has received more attention as news organizations dig into the accuser’s story.
Over the weekend, CNN found a tape of what appears to be Ms. Reade’s mother calling in to “Larry King Live” in 1993 and obliquely referencing an incident with a senator.
The Biden campaign flatly denies the allegation and has challenged reporters to investigate further before giving it exposure.
The candidate himself, though, has not responded, even as pressure mounts for him to do so personally.
Mr. Biden and his wife, Jill, appeared Thursday on the Instagram Live account of U.S. women’s soccer star Megan Rapinoe, but they didn’t raise the subject.
The audience on the message board accompanying the appearance, however, heatedly debated Ms. Reade’s credibility, and some wondered why Ms. Rapinoe didn’t ask Mr. Biden about the accusation.
In the North Carolina race for Senate, one of a handful that will decide control of the upper chamber, Democratic candidate Cal Cunningham has proudly touted his support of the #MeToo movement.
That makes his silence on Mr. Biden untenable, said North Carolina Republican Party spokeswoman Sasha Duncan.
“His handling of Tara Reade’s allegations is just further evidence that Cal Cunningham has no core convictions,” she said, adding that Mr. Cunningham backed the pro-women #MeToo movement only when it was politically advantageous.
The Cunningham campaign didn’t respond to a request for comment.
In Arizona, Democratic Senate challenger Mark Kelly told a radio station that he stands by Mr. Biden, drawing a sharp rebuke from the National Republican Senatorial Committee.
“Mark Kelly likes to say he’s ‘independent,’ yet once again he’s proving he has nothing but blind allegiance for his Democratic Party,” said committee spokeswoman Joanna Rodriguez.
In House races, Reps. Abby Finkenauer of Iowa, Donna E. Shalala of Florida and Lucy McBath of Georgia have all endorsed Mr. Biden and are now among the Democrats facing pressure from Republicans to turn against their party’s presumptive presidential nominee.
The NRCC said Ms. Finkenauer was a fierce critic of Justice Brett M. Kavanaugh in 2018, when he faced sexual assault allegations that were backed by scant evidence. “We need to believe survivors,” she said at the time.
“Finkenauer hasn’t called for an investigation, hasn’t demanded Biden release his Senate records and hasn’t even called on Biden to address Tara Reade’s accusations,” the NRCC said. “Does Abby only believe survivors when it’s politically convenient?”
Ms. Finkenauer’s campaign could not be reached for comment.
Mr. Biden’s defenders question Ms. Reade’s evolving story and say the Republican alternative, President Trump, has a far longer rap sheet when it comes to allegations of maltreatment of women.
Still, the allegations against Mr. Biden are damaging.
Some supporters of Sen. Bernard Sanders, Mr. Biden’s closest rival for the party nomination, say it cements their determination to choose another name come November. Others may avoid voting altogether, depressing Democratic turnout and hurting down-ticket candidates.
Michael Bitzer, a Catawba College political science professor, said the Republican attempt to capitalize on Mr. Biden’s troubles is part of a trend of making congressional races referendums on the presidential candidates.
“Just as we are likely to see Democrats tie every Republican candidate to Trump, no matter the level of office, Republicans are going to do the same,” Mr. Bitzer said. “Granted, Trump’s history provides more for Democrats to utilize on women’s issues, but Republicans are able to use these allegations in a turnaround to attack Biden.”
House Speaker Nancy Pelosi, California Democrat, said Thursday that she supports the #MeToo movement but added that Mr. Biden deserves “due process.”
“There was never any record that anybody ever came forward or anybody came forward to say something about it apart from the principal involved,” she told reporters. “I am so proud, the happiest day for me this week was to support Joe Biden.”