There were some tense moments on CNN's Crossfire Friday when Daily Show ringleader Jon Stewart dropped by and proceeded to tear co-hosts Tucker Carlson and Paul Begala to shreds. Stewart, who frequently takes jabs at the debate-style program on 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.