Republicans don't hate liberalism, they hate democrats and "liberals" is just another word for democrats in American politics. It's just a case of factionalism and the democrats can be just as bad.
I agree that democrats can be just as bad but regarding hate for "liberalism", sometimes you have to take people at their word when they say they hate something. Saying the words "I don't necessarily hate all liberalism" would sink any of the Republican presidential candidates. It's gotten so bad with the Republican party that all you have to do is call an idea they support "liberal" and they'll do a 180 and hate it.