I think this could cause the Dems some serious political damage. IMO it was a mistake for the women who are aiming to be Biden’s running mate to so quickly publicly disbelieve allegations against him when they were so quick to publicly believe allegations against Kavanaugh. You are right, allegations against Trump were, if true, more serious. Keep screaming “But what about Trump!” every time someone mentions Biden and see if it stops them bringing up Biden.
But, hey, the Dems are experts at finding ways to lose easy to win elections. They’re not very good at winning people over any more.