Repeatedly stifled by the mockery of comedian Jon Stewart, the nation’s largest conservative television channel seems to have latched on to a new line of attack in defense of its ethics: calling him a racist.

It all centers on a joke Stewart made about former pizza executive Herman Cain, who’s currently seeking the GOP nomination to the presidency in 2012. Stewart had ripped Cain weeks back for suggesting that if he were president, all legislation would be limited to just tree pages.

In typical form, Stewart used a slightly different vocal tone to make fun of Cain’s idea — which was apparently enough for Fox News to ask if Stewart was engaging in “racial comedy.” One guest even called it an “Amos and Andy routine.”

Stewart’s response: a highlight reel of his own funny voices, lovingly titled “Jon Stewart f#*ks himself with his own mouth.”

This video is from The Daily Show, broadcast Tuesday, June 28, 2011.