Trump is 74 and obese, two facts we do know about him, and that puts him at higher risk for complications and even death from COVID.  But counting in his favor is that he will presumably be able to get access to newer treatments, like antibody plasma from recovered patients.   Since he is purportedly asymptomatic today, it seems unlikely he would have been infectious at Tuesday's debate with Biden, since people with COVID are, from what I've read, only infectious in the 48-72 hours prior to the onset of symptoms.  But Biden is being tested as well, of course.

If a candidate for President becomes incapacitated (e.g., on a ventilator) or dies, what happens?  It can get quite messy, but here's an extended and informed discussion by election law experts.

It's hard for those of us living through this nightmare not to experience some Schadenfreude.  As a philosopher elsewhere wrote me this morning:  "The arc of the pandemic bends towards justice."   Given Trump's gross mismanagement of the pandemic, which has cost tens of thousands of people their lives, and millions of others suffering and misery, there is a kind of "justice" that it has now come back to bite him.  If he becomes seriously ill, it may give him a face-saving way to withdraw before his likely defeat.  But it may also plunge this dysfunctional country into further turmoil in ways none of us can yet anticipate.

UPDATE:  The latest this morning (9:30 am CST) is that Trump does have "mild symptoms" now, meaning that he may have been infectious on Tuesday.  What a mess.

ANOTHER:   So as of 11:30 am CST, roughly, the Bidens have tested negative.  Of course, false negatives are not uncommon, so we'll see.