JB Pritzker, Gretchen Whitmer, perhaps Gavin Newsom. Even Kamala Harris would have a better chance than Biden. Next to no one is voting Democratic because of Biden, people are voting against Trump. You could swap in literally anyone who isn’t 90% corpse and get at least as good a result, and almost certainly better. This idea that people would be turned off the Democrats because Joe Biden wasn’t the candidate is a joke and I don’t understand why anyone would be under the impression.
Post debate polls have had Harris up on Biden in swing states. Could she win? Maybe, maybe not. But it looks like she’d at least lose less badly than Biden. His debate performance was a death blow.