The person who looked best in the final Florida debate was Rick Santorum. That means Mitt Romney, who did well won. Newt Gingrich who did okay, lost. Gingrich needed a really solid performance and he only had decent performance. In the dying days of the Florida campaign, with polls suddenly turning against him, Gingrich needed a win and he didn't get it. He may have lost the state as a result of that debate.
Rick Santorum is competing now for the same space in the electorate as Newt Gingrich. He won the debate but he won't win Florida. Florida is a momentum state. If Santorum doesn't get out (or Gingrich), there is still one too many not Romney candidates in the race. The remaining not Romney vote will be split and it will effectively ensure that Romney racks up delegates very quickly. It will ensure Romney wins the GOP race. With Nevada coming up shortly after Florida time is quickly running out.