The way they made that sudden switch during the Dem primaries tells me that whoever is really in control of the Dem Party figured he was the puppet who had the best chance against Trump - someone they could portray as a moderate while pulling the strings behind the scenes.
They weren't the least bit concerned about or interested in Biden's ability to win ... the jackass, himself, told us he didn't need our votes to win. The democrats knew they were going to steal the election regardless of the candidate.
I think Biden was selected because he's the easiest to remove from office.
As I see it, they've two paths: A resignation because of failing health driven by a vote on the 25th Amendment. But it may be difficult to get 2/3 of both Houses of Congress to approve this so he could fight it and make a damn mess all over the carpet in the Oval Office.
So they may go with the second option: A resignation because of failing health spurred on by the threat of an investigation into Hunter that WILL lead to a guaranteed prison sentence.
In either scenario, Jill's going to be the real obstacle.
If this all wasn't so damn infuriating and frightening --- it would be interesting to sit back and watch this play out --- and take bets on how and how fast the RNC/GOP blows their response.