> But I am certain, that a big amount of his voters are full on pro free speech.

Oh, for sure, especially if you are talking about a big gross amount rather than a percentage.

A big part of it is the fact that in the two-party system of the US you don't need to like or agree with one party to vote it, you just need to despise it less than the other party.

I do agree that free speech is a core aspect of democracy. The highest authority is the common mob, the highest chamber the population as a whole. Speech is a crucial form of power the people ought to be allowed to exercise.