Barack Obama

In his first answer of the night, and on a few other occasions, Obama brought his new, effective stump speech rhetoric to the debate format, skillfully weaving his positive message with stinging jabs of Clinton's credibility. Mostly, though, he was inconsistent, intellectually tentative and positively Clinton-esque on the issue of driver's licenses for illegal immigrants. His answer was so fundamentally evasive (meandering to his final declaration of support) it rendered his critique of Clinton as an obscuring waffler null and void, at least for this debate. Lost 60% of the gains he made with his strong speech at last weekend's Iowa Jefferson Jackson dinner. (That's what the back of the envelope says, anyway.)

—By Mark Halperin