Try threatening the President and let me know what happens. Then go to a mall and proposition an 11 year-old for sex. Let me know about the First Amendment then.
Well of course there are laws against saying such things but they violate the constitution and are put in place because politicians like to limit speech. That doesn't mean that we should expand their role in deciding what can and cannot be said. I personally have no problem with someone threatening the President. In fact, it happens all the time. Even Eminem does it.
Don't get me wrong. I am dead set against the use of the F Word on TV. I think it is a very bad thing and is only used because of the supposed shock value and becuase it has become hip, mostly due to the Hollywood influence in our culture. Check out the John Kerry interview with Rolling Stone. The libs just want to make it as common as "a", "the" and "and".