and nobody will do anything to stop it

Many are trying, though options are severely limited by the fact that, two years ago, the entire US government was gift-wrapped and handed to fascists by a bunch of democrats who figured “why bother?”

I don't know who they'll run, but I know they'll be worthless

It sounds like you think there won’t be presidential primaries. Or perhaps you think you aren’t allowed to vote in them? You are. And what’s more, since participation is quite low historically your vote likely has quite a bit more influence in the primary than in the general election.