I think that many of Trumps' supporters, like many True Believers on each side of the aisle in this country, are narrow focus people.  They have only one or a very few issues that are important to them and if the politician meets their requirements in that area, the rest of what he does or doesn't do or say, they ignore.

Perfect examples here:

Abortion/woman's right to choose.

Banning guns/2nd Amendment rights.

If Trump is on the 'correct' side in either of those two issues, those advocates ignore everything else.  

Hillary and Bernie had the same type of single issue advocates/supporters.  

Few hoi polloi have a coherent political philosophy in the first place and even then there are people who are, for example social liberals and fiscal conservatives.