I think you're missing a big factor here: both candidates have a track record as president. We haven't had that in a long time, often it's only the incumbent with a record, which we usually associate as in their favor. Part of that record, for both of them, isn't due to anything they did, but the times they ran things are associated with them. And of course part of it they're each responsible for.

Despite all the rhetoric, Trump has a pretty good track record to the average american. Wars ending, dollar a gallon gas. In contrast, Biden doesn't look too good. Wars starting, groceries going up weekly. We can say what is who's fault and what is out of their control and whatever, that is just noise to all but decided voters. I think that this case will sway some away, sway some for that don't like what they see as political weaponization of the justice system, and all in all it stays in Trumps favor.