(from Simpsons Treehouse of Horror VII)
KODOS: It’s true, we are aliens. But what are you going to do about it? It’s a two-party system; you have to vote for one of us!!
MAN: He’s right; this is a two-party system.
HOMER: Well, I believe I’ll vote for a third-party candidate
KANG: Go ahead! Throw your vote away! Ahahahaha!