There was a similar dynamic in Washington, DC in the 90's, when Anthony Williams followed Marion Barry (who several writers have compared to Trump).
I could see Republican voters eventually souring on Trump somewhat if he was seen as being too incompetent to get their agenda enacted, except at this point I'm not so sure how much policy Republican voters even care about. Trump pisses off a lot of the right people, and to a large part of his base that is the agenda.