Being a comedian doesn't mean you're not telling the truth. The best comedians actually have the truth at the center of what they are saying, and it's theirt ability to put that truth into perspective that makes them funny.
What these guys do is expose the truth but in a way that is amusing. Typically they point out and mock the ridiculous and hypocriticial things that politicians (and others) are doing.
---------- Post added 2013-01-18 at 03:47 PM ----------
People should watch Jon Stewart's interview on Fox News. Very informative and gives perspective on what he actually does (stuff about him starts more at 7 mins in).