There's good reason to question whether Biden is up to the job, and if not, he shouldn't be president, let alone running for more.
But otherwise? Dem certainty that he'll lose is nuts. With a bunch more polls in, 538 has him down by 2.3 pct points after a disaster week. That's bupkis!
A Biden who survives the next couple of weeks would have beaten expectations in public and behind closed doors several times, demonstrating that the debate was in fact a one-off bad night. In doing so, he would turn the debate into a normal short-term effect.
I'm not at all confident he can pull that off! Not at all. But at this point, what it would take for him to continue would also mean significantly better polling.
That's all.
I’m ambivalent and trepidatious about a switch and agree generally with your point but: a possession where you don’t score is much worse when your team is behind than when your team is ahead. Status quo ante doesn’t mean much when it’s the result of a missed opportunity to change things.
No question that the debate at best was a missed opportunity...but mostly to convince people he's still in good shape, which (if he is!) will still likely happen.
Not to mention the crosstabs still tend to have him winning with the most engaged voters (people who voted in 2020, voters 65+) meanwhile Trump's strength is low engagement voters and he has virtually no GOTV apparatus.
