There were some tense moments on CNN's Crossfire Friday when Daily Show ringleader Jon Stewart dropped by and proceeded to tear cohosts Tucker Carlson and Paul Begala to shreds. Stewart, who frequently takes jabs at the debate-style program on The Daily Show, accused conservative Carlson and liberal Begala of being puppets for their respective parties. "You have a responsibility to the public discourse and you fail miserably," he scowled. "You're doing theater when you should be doing debate." At one point, Stewart even told a visibly irritated Carlson, "You're as big a d--k on your show as you are on any show." How uncomfortable was the segment? Rosie O'Donnell- Tom Selleck uncomfortable.