> You can wax poetically all you want about endowment by the creator, but try saying racial slurs on daytime TV and see how long that lasts.

You're conflating two senses of "free speech". Free speech is an ideal, which our society does not fully reach (as you correctly pointed out). But in the US, "free speech" is also sometimes used to refer to the legal protection from the first amendment. And in your example, that does apply. I can say all the racial slurs I want on TV, and it would be quite illegal to put me in jail for it.