As Politico notes, this is a weird type of attack against a "civilian", rather than a rival candidate. Why get into a public fight over the accuser's character? But then, this isn't a normal campaign, and they haven't exactly been using the normal playbook.
Politico miss the obvious, as they usually do. It is a very, very common thing to do (when possible) when accused of sexual assault (and also rape, of course). Because we've made a world in which many people believe that only the only women who can be attacked are saints.