Voting public has very short term memory, perhaps the exceptions being immigration and guns. I know my state that went strong for Trump had a survey at the local pro-gun Facebook page for the election and Cruz barely came out on top. Why, because most of the 2nd amendment nuts did remember Trump's position on guns (longer waiting period and a ban on assault weapons).
@Cripplecreek
It depressed me that Christians (of which I count myself) were some of the most forgetful voters in the election.
I read an article about these people the other day and I fear for the future of out nation. They were interviewing people who believe Trump has raised the minimum wage by decree, Trump can fire congress and supreme court at will (but doesn't due to his desperate attempts to work with them) and he's forced auto makers to built plants here. None of these things are true but these idiots believe them whole heartedly.
On the bright side I think just as many are walking away from Trump and it remains to be seen how the GOP deals with it and if they try to salvage anything. Personally I'd like to see the GOP make a hard turn toward federalism.