Democratic presidential candidate, Senator Joe Biden
Directly challenged Clinton's frontrunner status by making a strong case that her divisive image and history makes her ill-equipped to win a general election, or work with Republicans to bring about health care reform and other changes. It was the move every anti-Clinton candidate, strategist, and pundit has been waiting for. But he did it awkwardly and back-pedaled with a clarification that he was referring only to policy. Sold his Iraq peace plan as a statesman, not a firebrand. Assertively belittled Rudy Giuliani's foreign policy credentials.
—By Mark Halperin