It's a mystery why age is a problem for Biden but not for Trump in a general election view. Seems to me that the real problem is Dems who don't want to admit to be biased against a President Harris should the worst happen to Biden.
But I heard one MSNBC talking head opining that the debaters were hoping that Trump would choke on a cheeseburger, after which Chris Hays opined that hey, he's an old man so he's likely to just drop in his tracks.
Dems are bigoted that way.