The 1st shooting was in a whisker of succeeding.
To play the tin-foil-hat game (not without some substantiation), for a shot ear it seems to have healed remarkably.
If it was a political thriller, there's any number of movie plots (and in-universe plots) that a decent screenwriter could invoke that have the same in-universe appearance as this real life one looks to have.
The late June fallout from his reaction to the Jan-6th reports do sort of beg a staged distraction (depending upon who is orchestrating it, it could be indeed as ruthless as it turned out to be), with or without advanced complicity on his behalf. But that's Conspiracy Theory Central, mostly.
Having had one shot at that (pun not
entirely intended), it wouldn't be too much of a stretch to organise another, post debate 'incident' (or, slightly more of a "sane" theory, the first being real they decided to gain a similar boost by their own hands). The main evidence against this is that
this (alleged) perp was taken alive, unlike the first.
Balance of probability, though, things were just crazy enough to be real. Should another apparently unimaginative 'echo' of the same sort of theme happen (not that guns aren't probably the 'default' go to, by the suitably disaffected, in the US, which skews
that element of probability), we can probably start to look at the Bayesian analyses with actual seriousness.