It won't matter either way, Democrat or Republican, his challenges would be about equal.
But remember, if he wins he would be sworn in with more political capital than any POTUS in our lifetimes and maybe more than any ever.
If he prevails after all the institutional forces on the planet through everything they had at him, his victory would be decisively the new political norm.
No politician in America would want to cross him.
This is nonsense unless you want to elect a dictator.