Last night, Jon Stewart sized up the recent "jokes" of Rick Perry and Herman Cain, and spots a trend in the sense of humor of the GOP candidates. The Texas governor's latest flirtations with birtherism ("it's fun to poke at him," Perry said of the doubts about the president's birth certificate on Tuesday) and Herman Cain's now-withdrawn proposal for a 20 foot-high, barbed wire, electrified border fence serve as the jumping off point for The Daily Show host. "Perry's birther embrace, Cain's Mexican fence, bug-zapper idea, a pattern is emerging. See if you can spot it," he says, before cuing a comprehensive 20-second highlight reel of every controversial thing said by the GOP contenders over the last month: