I have a feeling that the nomination will go to Kamala Harris. Some of them do seem to be tripping over themselves to endorse her, including the Clinton's. Harris herself is talking in terms of perhaps a mini primary election. Is that the way forward, given that time is rather short?
The withdrawal of Biden has a ring of inevitability about it. His cognitive abilities and mental acuity have visibly declined a lot and seem sufficiently compromised that it his ability to do the job for another four years is in serious question.
Whatever now happens, I have everything crossed that the Democrats can pull themselves together sufficiently to tackle the Trump problem. I like to think that Trump is not invincible, but the Democrats do need to get their act together and unite behind the right candidate, whether that is Kamala Harris or not. I'm not holding my breath though.
I think a younger candidate is needed (Kamala Harris does fit that bill too). Neither Biden nor Trump are spring chickens, Trump being in his very late seventies and Biden at 81.