Michele has zero political experience, had one real-world administrative job that her husband got her and that was so critical they didn't even bother to replace her when she left. Plus, she doesn't want to actually do the hard work she'd need to do to campaign and pretend to run the country. She would rather just be a complaining megawealthy haridan who may or may not have a dick.
It's likely to be Kamala, or possibly Warren. That's how thin their bench is.
I think they are staking it all on vote harvesting and mail-in fraud. So, the popularity of their candidate means nothing. No one likes Hillary? Who cares? Michelle doesn't want to do the work? [shrug] Elect Michelle and Valerie Jarrett will do all the work.
I am being flip. But my overall point is serious: the Democrats do not need an electable candidate this year. They plan on stealing it. They do not have a Plan B. They just need someone in the chair who won't cause a problem. Joe is someone who would cause a problem.