Scarane is one of more than a half-dozen progressive House and Senate challengers — almost all of them millennials — who have said publicly that they believe Reade’s claim that Biden sexually assaulted her in 1993 when she worked as his Senate aide or otherwise spoke out in support of her. Though most are long-shot candidates with limited resources, their remarks could stoke division at a time when Biden is trying to unite the party’s warring factions. Their stance also risks exposing a rift between some younger and older Democrats as Biden works to strengthen his position as the Democratic nominee.

“There is a generational component,” said Peter Daou, a progressive consultant who has advised some Democratic candidates who said they support Reade. “This is part of the entire divide between people who came to politics through Bernie Sanders, principled progressivism, leftism. What I’ve found is that for these types of activists and voters, there tends to be less willingness to be either incremental or to compromise with the Republican Party. It’s a belief that the way we win is by adhering very firmly to our principles.”

Biden has vehemently denied Reade’s allegations. On MSNBC last week, he said, “No, it is not true. I am saying unequivocally it never, never happened, and it didn’t. It never happened.” Biden’s former Senate aides at the time said that Reade never complained about him to them, and no Biden staffer has corroborated her assault claim. Three people have said Reade told them about the alleged assault roughly around the time she said it happened or a few years afterward.

The Biden campaign did not provide comment for this story. Sean Coit, a spokesman for Coons, said, "Since these allegations first surfaced, the Biden campaign has urged reporters to look into them and the campaign is urging the Secretary of the Senate to release records of any complaint Ms. Reade might have filed. Sen. Coons believes all allegations of assault should be taken seriously and investigated, and he believes Vice President Biden and his campaign are handling this appropriately."

Forty percent of Democratic voters under the age of 45 — the core of Sanders’ base — said the party should pick a different nominee after watching a video of Biden’s denial, according to a Morning Consult poll, whereas only 15 percent of Democrats 45 and up said the same thing. Another survey by Monmouth found that 45 percent of all voters between the ages of 18 and 34 said Reade’s allegation is likely true — a larger portion than any other age group.

Biden has struggled to win over young people in the primary, and some Democrats worry about a rerun of 2016, when Hillary Clinton failed to rally some of Sanders’ former supporters and lost to Donald Trump by a small margin in the critical battleground states of Pennsylvania, Wisconsin and Michigan. Biden has worked to avoid such a scenario by talking positively about Sanders and his supporters, and announcing that he will create policy task forces with the Vermont senator.

Lindsey Boylan, a 36-year-old running in New York against House Judiciary Chairman Jerry Nadler, has tweeted multiple times about Reade, including her frustration with House Speaker Nancy Pelosi’s defense of Biden and remarks that “Joe Biden is Joe Biden.”

She said that her first political memory was of the controversy surrounding Bill Clinton and Monica Lewinsky, something that she believes the media and Democrats handled poorly, and she wants to avoid such an error.

“I feel like the adults in the room at the time really did not handle anything about that with care,” she said. “The world I grew up in — my early adulthood and my first awareness of politics and the business world — is not a world I accept for my daughter.”

The divide among different generations of Democrats in their treatment of Reade’s allegations has been evident even among some elected officials. Sen. Elizabeth Warren, a leading progressive, unequivocally said she trusted Biden: “I saw the reports of what Ms. Reade said, I saw an interview with Vice President Biden. I appreciate that the vice president took a lot of questions, tough questions. And he answered them directly and respectfully. The vice president's answers were credible and convincing.”

Rep. Ayanna Pressley, a member of the so-called “Squad” who endorsed Warren in the primary, wrote a nearly 700-word Medium post involving Reade’s allegations titled “It’s 2020 and we still don’t know what survivor justice looks like.”

In it, she suggested Biden’s response fell short. “We are in the throes of an election of the greatest consequence — one that will determine if core rights and tenets of democracy survive in this nation. The stakes cannot be overstated. But I have no patience for any person who tells me that is a reason to lower my voice. I reject the false choice that my party and our nominee can’t address the allegations at hand and defeat the occupant of the White House.”

Several of the progressive challengers who believe Reade said they are concerned about Biden’s ability to defeat President Donald Trump, who has been accused of sexual assault and misconduct by multiple women, because of the allegation. But Rebecca Parson, who is running against Washington Democratic Rep. Derek Kilmer, is one of the few who has called for Biden to withdraw from the race. She wants his delegates to be reallocated, and for other Democratic candidates to restart their campaigns so the party can nominate someone else.

"We need to go against Trump with somebody who he can't attack on charges of hypocrisy,” she said. “Trump will not hesitate to seize on it and accuse Joe Biden of hypocrisy. Unfortunately with Trump, it doesn't matter that he has extremely serious allegations against him.”

Biden’s supporters have argued that progressives such as Parson are politically motivated because they want a left-wing candidate such as Sanders to be able to rejoin the race and win. Parson denied that, saying she would support moderates as well as progressives who restart their campaigns.

Despite their beliefs about Reade’s accusations, most of the challengers interviewed for this story said they would vote for the Democratic nominee regardless, though some hope that Biden somehow won’t end up being that person. In the Monmouth survey, about one-third of voters who think Reade’s accusations are probably true said they also would vote for Biden — a reflection of the large number of Americans who want Trump out above all else.