IMO the election will come down to 2 issues, possibly 3:
1. Dems ability to continue to leverage the Dobbs decision, and highlight Trumps (gleefully admitted) role in it. It's crucial to not understate how batsh*t crazy and against the majority opinion what the SC did was, and how angry it rightly has voters. 70% of Americans think abortion should be legal, and it's been banned in states because, essentially of the acts (and lies) of 2 judges and a President.
2. Donny's legal fun. While the cases to date have been somewhat esoteric (lying on financial statements, defamation) the upcoming ones should be far more damaging to a candidate. There can be almost no doubt on the documents verdict, though another Trump appointee is holding things up. Jack Smith's case will be brutal in keeping Jan 6th forefront in the news. And I still don't see how voters can hear Trump soliciting voter fraud in Georgia and not recall it's really not a witch-hunt when we hear him doing the witch bits. Plus, he's almost 80 and going to be spending huge swathes of his time travelling to and from courtrooms - this will impact his ability to campaign. I think the more Trump is back in the daily news cycle and tied to the above crimes, as well as undoubtedly saying more insane sh*t like he's been doing for the past 3 months (seriously, go listen to some of the nonsense) it'll remind independents of who he really is, not the rose-coloured pre-covid economy stuff he's trying to peddle.
3. If Biden falls/gets ill/dies. Obviously.