Throwing some link love to PZ (who doesn't need it). Seems that Ebert thing was a very poor attempt at satire. He covers the point quite well: If there's no shortage of people out there who say it with a straight face, it doesn't really work.
It kind of reminds me of one criticism I heard about "Good Night and Good Luck," about McCarthy's part in the Red Scare: Some people apparently thought the actor playing McCarthy was too over-the-top to be taken seriously as an actual political figure. That wasn't an actor. It was old footage of McCarthy.