Mitt Romney stopped by The Tonight Show last night to chat with Jay Leno about Rick Santorum’s “worst Republican” dig and what, as president, Romney would do to change the current tax code — basically serving as human Ambien for late-night viewers. Then Leno challenged Romney to a game of political word association (not unlike the one Jimmy Fallon played with Michele Bachmann last year), which Romney played so straight and serious, the audience maybe thought he was being ironic? Asked to describe Chris Christie, Romney said “Indomitable,” which cracked up the audience that clearly was waiting for a word in the one-to-two-syllable family. For Marco Rubio? “The American Dream,” Romney said. Mitt, that’s three words! Finally Romney made a sorta joke when Leno got to Rick Santorum: “Press Secretary,” Romney said, still breaking the rules of the very simple game, but we’ll let it slide. Just this once. Watch our video for the game segment and see the full interview here.