Personally I feel that Bernie Sanders is still, despite *everything*, the best chance Dems would have to win office IF -- and this is a BIG 'if' -- Biden were to take leave of the stage. Sure, from a support standpoint, Bernie didn't have what it took to beat Biden, but who is to say that with Biden out of the running entirely that Bernie wouldn't have the best chance given that shake-up? Certainly there was nobody else other than Bernie who was 2nd to Biden. It is safe to say that if the goal was to have a chance at winning, Bernie would be the guy.
If it's not about winning, but rather, having a 'true' Democrat, then of course he would not be the selection because, as others have so aptly pointed out, he's not a Democrat, really.
For what it's worth, I don't think he's raped anybody.