Former North Carolina senator John Edwards
Took his now-familiar position in the shadows, as the two front-runners duked it out with alarming intensity. Nevertheless, made the best of the situation: on a level playing field, Edwards would have won the debate by a wide margin. Happy to step in as the voice of reason (or to serve as an equal-opportunity dueling second), and was strong and assured when laying out his own goals as a candidate. But while his two rivals fight each other, he is still fighting the media's instinct to disregard his "when I am the nominee" assertions and his ideas.
Bottom line: Monitor the quantity and quality of the local and national coverage of the debate, and see if his numbers move accordingly.
—By Mark Halperin