Although we were psyched to see Juno screenwriter Diablo Cody on Letterman last night, the actual interview was a bit of a letdown: the two didn't really cover ground they hadn't already covered back in 2006 during Diablo's first Late Show go-round to promote her book Candy Girl. But Letterman's first guest, Democratic presidential candidate John Edwards, did not disappoint! (Who would've thought that a politician would be more fascinating than a former stripper?) After quizzing him on Monday's night's Democratic debate and ensuing "melee", Letterman asked Edwards about Barack and Billary's petty bickering ("When it gets in the ditch, it doesn't add much"), how all the Democratic contenders get along ("We can't stand each other") and, as a parting gesture, requested to touch his famous tresses. Ever the good sport, Edwards agreed...then responded by initiating a mock girlfight. Clip above.