He'd lose. Parody is protected. Hustler Magazine, Inc. v. Falwell, 485 U.S. 46 (1988)
Not so sure I agree with you on that front. In Falwell, the Supreme Court focused on the fact that the fake “ad” for Campari that was the parody making fun of Falwell (alleging he had a drunken incestuous relationship with his mother in an outhouse) had a disclaimer at the bottom clearly stating that the “ad” should not be taken seriously, and was not, in fact, real.
If you watch the video of Colbert, it seems that he actually moves from satire early in the monologue to a political commentary where he’s knowingly and maliciously using falsehoods to defame the character of the President. Around the 10:30 mark, when things get salty, all real semblance of satire seems gone from the speech—including where Colbert says he’s not afraid to insult the President to his face.
At my daughter’s campus I’ve heard there is some nutcase out there in the “free speech” area blasting the kids with crap under the guise of religion. Confronting girls and calling them whores and calling for them to repent. To heed the lessons of Sodom and Gomorroh, etc. Sounds like one of the Westboro Baptist nutcases.
Wouldn’t telling some poor kid that she is a whore be defamation? Of course it’s finals time, and who can afford a lawyer. And the nut is probably LOOKING for a legal fight as he do like the Westboro folks do and aim to win a bunch of money - knowing all the tricks of the law.