Gavin Newsom vs DeSantis debate and Newsom saying he is loyal to Biden makes me think he is at least considering. Bill Maher endorsed him. It felt like a "look at me" "look at me" in order to get support from the establishment.

Hillary is another solid option, she has the advantage that she will fire up the anti-Trump people, revenge of sorts. But I've not seen anyone seriously pushing her, maybe they figured she is to much of a liability with the Epstein stuff.

 Michele Obama is the other candidate, being a woman of color, married to a gay guy, that is still very popular, makes her an obvious leftist choice. 

Newsom - lots of the moderate left and centrists will vote for him as they see him like an old-school democrat.

Hillary - anti-Trump sentiment, she is the weakest as TDS is still rampant so they don't need her.

Michele - good far-leftist candidate that would also get old-school democrats to vote.