They already don’t. The closest they had to a candidate was nikki haley and she is now just as hated by “the base” as cheney or romney.
And for as much damage as trump et al have done: It is well worth looking up clips of the times he said stuff like “I am not against vaccinations” and actually got booed by the crowd. He is not the source of the evil and is instead just a symptom of it and needs to play to his base as much as any politician.
So if he does have a truly tragic and sad heart attack: There basically won’t be a republican candidate for POTUS this fall. We’ll just speedrun to the “they stole the election, get your guns” stage of 2024.