After 19 debates, one may think that there's nothing new that any of the four remaining candidates could say. But as Jon Stewart noted of Tuesday's second-to-last one, they can still surprise us. We saw Mitt Romney mixing up Seinfeld characters and Rick Santorum being mocked for (gasp!) being reasonable. Best of all, when the candidates were asked to sum up their campaigns in one word, the responses spoke volumes. There was flip-flopping Romney calling his campaign "resolute" and apocalypse-predicting Newt Gingrich somehow calling his "cheerful."