Mr. Biden’s advisers indicated on Sunday that the accusation would not dissuade him from entering the 2020 campaign, which they suggest he still intends to do at the end of April or just after. But Ms. Flores’s claim, and Mr. Biden’s attempt to rebut her story without dismissing it — or her — offered a vivid illustration of the #MeToo-era challenges that await a 76-year-old political veteran known for his close physical contact with women and men, including hugging, kissing and touching them…

“Maybe Biden and other male politicians should observe their female counterparts,” said Gloria Steinem, the feminist advocate, in an email on Sunday, noting that since “women candidates are unlikely to hug and kiss men they don’t know, male politicians could refrain from hugging and kissing women they don’t know.”…

“Flores has a fierce but small following,” said Jon Ralston, a longtime Nevada political analyst. “She lost badly in her last two races. She fell out of favor with many after her 2014 disaster and subsequent poor showing in a run for Congress.”