Republican race torn wide open by Gingrich win

A Republican race that was interesting has now become fascinating. Even before this morning's remarkable result in South Carolina, a rumbustious performance in debates had galvanised Newt Gingrich, and Mitt Romney's serene progress was seriously unsettled, his support taxed at a seemingly higher rate than the 15 per cent levy he apparently pays on his large income.

But then, in the early hours, came a clear-cut victory for Gingrich which totally upends this contest. And what is significant about this primary is not just the result, but what has been learnt about the candidates in some of the less highlighted moments of the campaign in this state.

In the rough old world of politics, candidates' answers to softball questions are an odd place to seek enlightenment – especially amid the exchanges in Thursday's candidates' debate in Charleston that may have been some of the most destructive in those parts since Confederate gunners bombarded Fort Sumter in 1861 and set off the American Civil War.

Once again South Carolina's Republican primary has proved why it's one of the most intense and entertaining stops on the road to the party's presidential nomination. On Thursday alone, Rick Perry – by now a rather sad and lonely cowboy – pulled out, the underrated Rick Santorum was belatedly awarded victory in those long-ago Iowa caucuses, and Marianne Gingrich unloaded her truckload on her ex-husband.

That night John King, the CNN moderator, broached Marianne's “open marriage” allegation, and was repaid by Newt with a volcano of invective (against the media rather than his former spouse) that is surely without parallel in modern presidential debates. It merely confirmed what we all knew, that the former Speaker owns an extremely sharp tongue. But later came the softball question to each of the four would-be successors to Barack Obama: if you could redo one thing in the campaign, what would it be? And the answers were oddly revealing.

Ron Paul, the puckish 76-year-old libertarian from Texas, said he would have spoken more slowly. Reasonable enough: his demands for the abolition of the Federal Reserve and a return to the gold standard tend to come out as machine-gun fusillades. Santorum, who outlasted Michele Bachmann, Herman Cain, Jon Huntsman and Perry, understandably declared

he would change nothing. And why should he? He's beaten every expectation and is still standing. Whatever happens next, the faded Santorum brand has been resurrected.

Mitt Romney raised one of his few laughs of the night when he said he would have worked harder in Iowa to get the 25 extra votes that would have given him victory, before pivoting back to criticise Obama. It was the eternal Romney, disciplined, focused, but rather dull. As for Newt, he was by now in more genial mode. He maintained that if he could do something again, he would have dispensed much sooner with the regular staff running his campaign when it almost came to grief last summer. Instead, he maintained, he would have gone for broke from day one on “big ideas”, promulgated on the internet. In short, the nice Newt, broad brush and visionary, to set alongside the nasty Newt of a little earlier.

Last week the combination proved ideal. Newt's task, of course, was to do really well here, in a southern state next door to his native Georgia. Hyperbolic as always, he warned a few days ago that the primary would be an “Armageddon” in which “they” (ie Romney and his well-oiled attack machine) would stop at nothing to drive him from the race. But if they fail to do so, the reason is simple.

In South Carolina, of course, Gingrich has had the big advantage of playing at home; he knows how its politics work. But he's also been doing something else, tapping into something visceral in the current Republican party. Part of it is anger. Which is why his eruption against John King and the despised “mainstream media” forever biased against Republicans, went down so well, whatever the state's Christian evangelical Republicans think of his marital record.

Newt's a symbol too of a conservatism that delivered results. In the decade before George W Bush won the White House, Gingrich was the most influential Republican in the land. Ron Paul may be a purer advocate of smaller government – but if there's a Tea Party standard-bearer now, after the withdrawal of Bachmann and Perry, it's Gingrich.

Romney is still favourite to capture the nomination. But last week was his rockiest yet. In the end the Mormon dog never barked here, at least out loud. But in the debates on Monday and Thursday he was flat and often evasive – disastrously when he quibbled once more over the release of his tax returns, an innovation pioneered by his own father back in 1967. The tax question was inevitable, but Romney seemed caught by surprise. The audience boos showed that Newt Gingrich (who released his own returns earlier that afternoon) wasn't the only one in the hall asking: what on earth do you have to hide?

To be fair, Romney is unfortunate to have Gingrich as his main opponent in a year when debates have never been so numerous and important. He's better at them than in his first White House bid in 2007-08, but still wooden and stiff. By contrast, debates play to Gingrich's strengths: his ability to think on his feet and to sound knowledgeable on anything under the sun, his instinct for soundbites and for the rhetorical jugular.

A few days ago, there was much talk that Romney could wrap up the nomination in nine days' time in Florida. He still could, and of his final triumph there is still not too much doubt, barring a disaster that brings a late candidate into the field.

Here as in every red state, Republican voters knew Romney offered the best chance of victory. Equally, they know that Gingrich carries far too much baggage, and not only marital. As House Speaker in 1997, he was fined $300,000 for congressional ethics violations; in that job his management style was chaotic. What would he be like in the White House? Republicans want to make the election about Obama and his failings. But if Gingrich is the nominee, the election would be a referendum on their man, and he would certainly lose.

Post-South Carolina, the primary calendar favours Romney. The party establishment backs him, and Republicans invariably choose the establishment's man. As Bill Clinton put it: “Republicans don't fall in love, they fall in line.” But Romney needs a proper fight. And whatever one's opinion of Gingrich, he's nothing if not entertaining.

Poll upset as New Gingrich wins South Carolina primary