31 January 2012 Last updated at 21:39 ET

Article written by Mark Mardell North America editor

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Florida piles pressure on Gingrich

 

Romney's campaign was revitalised after his South Carolina defeat

This victory proved some of the truths strategists prefer to speak behind closed doors, not on cable TV. Money matters. Negative works. Go for the kill.

The biggest losers in Florida were those who like their politics civil, reasonable, and with the emotion stripped out.

Mitt Romney proved himself quite an operator. He crushed Newt Gingrich with a series of very negative TV adverts, attacking the former speaker's character and suitability to be president. He showed some fire in the debate.

But above all this came down to money. He spent at least $16m in Florida in the last month alone. He put out 13,000 TV ads. Gingrich had around 200.

By contrast Newt Gingrich pulled his punches in the debates, tried to be presidential and just didn't make much impact. He drew back, to an extent, from attacking the way Romney made his money. He repeated the charges, added to them a little, but then pulled back.

There was no display of a killer instinct. Gingrich's appeal is his curmudgeonly aggression and barely suppressed fury with the state of the world. When he doesn't have fire in his belly he doesn't inspire the angry conservative base who gave him victory in South Carolina.

I don't doubt that Newt is genuine when he stands in front of signs reading "The Next 46 States" and says that he is going to contest every state and win. He certainly might do better in some of the southern ones than the microcosm of the USA that is Florida.

He might be right. I suspect there will be some more good news for Newt sometime in the next few months. There'll be thrills and spills along the way, that some will declare have "upended" the campaign, just as they did after South Carolina.

But does he want to drag out the agony of almost inevitable eventual defeat right until Super Tuesday in early March? He probably does. But the pressure will be on for him to quit, for the sake of the party.