In tonight's debate, Newt Gingrich failed to live up to the high expectations that have been set by his previous debate performances. Mitt Romney, who had been on the defensive in the last few debates, shifted to offense. Romney did a good job attacking Gingrich, and managed to look tough without looking nasty. Gingrich defended himself fairly well at first, but he showed vulnerability as time went on--near the end of his extended one-on-one exchange with Romney, Gingrich was (uncharacteristically) at a loss for words for a moment.
But the debate was not a clear-cut victory for Romney. His central line of attack against Gingrich was Gingrich's lobbying and taking money from Freddie Mac. Romney would have done better to directly attack either Gingrich's lack of conservatism or lack of electability. The lobbying charge would presumably be aimed at Gingrich's electability, but is not as direct as, for example, Romney's earlier attacks that Gingrich is "zany" and undisciplined.
Romney showed discipline when attacking Gingrich, but made a gaffe on the subject of illegal immigration. When asked how illegals would be forced to return home if they were not "rounded up," Romney explained that illegals would do "self-deportation." Romney went on to describe that if employers didn't hire illegals, illegals would not be able to find work and would return home to begin the process of legal immigration.
Ironically, when Rick Santorum was asked whether "self-deportation" was feasible, he immediately said that it was and that it was already happening, with many illegals returning to Mexico due to the bad economy. Regardless, Romney's use of the phrase "self-deportation" makes an easy sound-bite and could hurt him by making him appear soft on illegal immigration. Romney may have been attempting to curry favor with the Cuban vote in Florida, but a gaffe is a gaffe.
Fortunately for Romney, he dealt with the tax return issue quickly, was not challenged on Bain Capital, and largely was not attacked for Romneycare or flip-flopping.
Gingrich did not get the opportunity to have a stand-out moment in the debate. The debate moderators never gave him a chance to attack them for being too liberal.
Santorum was mostly out of the debate, since the action focused on Romney and Gingrich. Interestingly, Santorum chose not to go on the offensive against either Romney or Gingrich until his closing remarks. Meanwhile, Ron Paul was irrelevant and received little attention.