That's such a crock Ivan. Comedy is not inherently liberal, and making fun of things as they are - or simply making day-to-day observations funny - doesn't mean you are going to change them or attempt to.
So much of humor is about making fun of people, relationships - nothing to do with politics. And as I mention elsewhere there's always great fart jokes :-) And scatalogical humor, blue humor, insult humor (Rickels, anyone?) joking about racial stereotypes and race relations.