trump might die, but assuming he is alive, he will be in the general election. It amazes me, but him being arrested, convicted, or even fleeing to Russia will not keep him out of the general election. I would assume we would have some sort of law that says convicted felons, or fleeing traitors were not allowed to run for president, but there is no such rule. I would assume that a major party would never nominate a convicted criminal, but the party of trump definitely would.
I might be wrong, but it appears to me that the future is very laid out. trump can only win the nomination, and only lose the general election. The one caveat I will say is that if he dies, I think then maybe his supporters will not vote for him.
Or I might be missing an option. If I am, I am definitely all ears.