Style: Carefully and calmly made his case against Gingrich's past. Looked tired. Lacked moments of grace and optimism. His usual tense, awkward tics all were on vivid display, perhaps heightened by a bad two weeks. Substance: Overall, a little vague, especially when talking about the economy. His worst moment: Still unable to give a smooth answer to the tax returns question, despite obvious intensive preparation. His best moment: A crude, inartful but sustained attack on Gingrich's ethics and Freddie Mac ties eventually wore Newt down, capped by a stark "influence peddling" line. The main thing: Dominated much of the night by systematically unloading his latest opposition research on Gingrich but never created a moment that truly broke through. His focus on his chief GOP rival meant he didn't drive his anti-Obama message as much as usual. Regained his former presidential mien and seemed to be the only candidate who at least partially fulfilled a game plan on the stage, successfully breaking the circuit on the South Carolina debate dynamic. But his muted killer instinct and apparent worry about making an error diminished an otherwise solid performance. Style: Low-key, confident delivery. Mostly adept at deflecting charges. Often passed up explicit opportunities to take on Romney. Like his chief rival, looked and sounded tired. Substance: Talked tough on Cuba, out-pandering Romney to the Cuban-American community. His worst moment: Chose not to rebut Romney's initial flurry of hard charges. His best moment: His recitation of his long history in the conservative movement contrasted mightily with Romney's weaker response immediately before. The main thing: Played more defense than offense with Romney. Unable to draw on energy from the hall as in South Carolina, since Tampa crowd involvement was near zippo. Rarely got to play his recent winning cards: media bashing, liberal elite bashing, Obama bashing. This debate won't necessarily slow his momentum but it will not add another rocket. Style: An air of resignation until the very end, when he showed some passion; otherwise low energy like everyone else. Substance: Little opportunity to flaunt his stuff but displayed his smarts on occasion and gave a strong answer on housing issues. His worst moment: After being largely shut out of the opening Romney-Gingrich colloquy, failed to seize his moment with differentiating riff. His best moment: Reprised his impressive him-versus-Romney/Gingrich comparison on conservative credentials from the South Carolina debate (but managed it only in the debate's closing moments). The main thing: If voters are turned off by Romney-Gingrich jousting, he might have scooped up some votes just by staying out of the mess. Solid throughout - but solid isn't enough any more. Style: Played the role of calm wise-cracker rather than intense slasher. Substance: Again missed too many opportunities to explain himself and show off his distinct agenda to a wider audience. His worst moment: Still seems squirrelly on whether he will run outside the GOP if he loses the nomination - because he IS being squirrelly about it. His best moment: His mini-lecture on the macroeconomics of the housing crisis was accessible and clear. The main thing: His heart seemed less into the competition than in past debates, perhaps because he isn't overexerting himself in Florida's winner-take-all contest. Grade: C-