Democrats will probably, switch in Gavin Newsom in the last minute to save democracy. They will attribute it to doctors saying Joe Biden has an ailment that will prevent him from exercising his duties as US President. This is after a doctor expert of the Democrats gave Joe Biden a clean bill of health.
So how do you think this ends? You sound like you believe the democrats are simply stupid, and will run Biden to the end of this.
Certainly a possibility. But I'd argue that Newsom isn't much better. California politics are extremely unpopular everywhere else. That would be like a cross between Kamala and De Blasio. Now, if they pulled something like Michelle Obama at the last minute, well I don't think Trump would stand a chance.