John Heilemann thinks the Romney campaign needs a margin of victory "that screams that they have decapitated Gingrich, and then played soccer with his severed head":
What margin will convey that image? At this point, I'd guess the consensus among the political class is that it will have to be in double digits. Anything less will raise questions about how Gingrich — despite being outspent four-to-one in Florida and running a pathetic, at times abominable, campaign here — managed to bounce back at the close. And if by some remote chance Gingrich manages to finish within five points of Romney, the outcome will not just leave him with his noggin on his shoulders but both pissed off and emboldened.