He didnt change the republicans base, the evangelical base has always been like this. Republican elites hate their base but they need them, so they could get away with doing thing that didnt matter and please them while getting tax cuts for the wealthy. Now R Elites have to get in the mud with the hogs.
This is just a continuation of the Tea Party. If they hated what their base is, they should of killed that movement instead of letting it fester in their party. Why there are so many conservative democrats now because they are basically republicans.