7.00pm: It's New Hampshire primary result night – and you could cut the tension with a baseball bat. As Newt Gingrich would say, let's be frank: barring an upset of apocalyptic proportions Mitt Romney not only has this in the bag but is already half-way to South Carolina.

But politics is a complex beast and just winning in New Hampshire isn't enough – it's by how much and over who that makes tonight's results important.

We could speculate on the possibilities of Romney losing but they are so slim that we may as well discuss the awesomeness of unicorns.

For the candidates not named Romney, it's not the winning but the taking part that counts.

7.03pm: To make sense of the result tonight, think of it as four individual elections:

1. Mitt Romney versus Mitt Romney
Will Romney 2012 edition do better than the Romney 2008 edition? In 2008 Mitt got 32%, finishing second to John McCain. If he repeats that result then he is in trouble.

2. Ron Paul versus Jon Huntsman
Jon Huntsman desperately needs a second place finish to stay credible and win some airtime, and to do so he needs to overtake Ron Paul. Paul flattered to deceive in Iowa, consistantly polling second but finishing third. Will he do so again? And does Paul have a 20% ceiling that he just can't break in terms of support?

3. Rick Santorum versus Newt Gingrich
A fifth place finish would be a disaster for Santorum, since it would reinforce the idea that his Iowa result was a one-off, thanks to the conservative eco-system of Iowa and his focus there, and nothing to do with Santorum as a possible candidate. Gingrich too needs to do better, to show that his Occupy Mitt Romney routine carries any weight with Republican voters.

4. Rick Perry versus Buddy Roemer
Perry had a miserable result in Iowa and according to the polls is due for an even worse result this time out. Maybe he should have stayed in Texas. If he loses to the submarine-profiled Buddy Roemer then the voices calling on him to quit will grow louder, even before South Carolina.

Polls don't officially close until 8pm but many will have closed at 7pm – and the exit polls are starting to come through, so here we go.

7.12pm: Our contest to predict the result of the Iowa caucuses was such a runaway success that we have decided to repeat it tonight. I can reveal that among the prizes is a "Why Women Love Rick Santorum" button badge, as well as the obligatory Guardian pencil.

Take part now.

Placards in Manchester, New Hampshire. Photograph: Emmanuel Dunand/AFP/Getty Images

7.14pm: In the traditional manner of American elections, the television networks and the Associated Press will call the result when they have enough information from the count to match their exit polls and forecasting.

In case like this one, my guess is that the networks will call the primary for Mitt Romney within nanoseconds of the polls closing at 8pm ET. That's usually the end of things. But not tonight.

7.32pm: We have live updating results from New Hampshire – and a recap of the Iowa poll – here.

7.39pm: The first actual results are coming in from places were polls closed earlier. Mitt Romney has steamed ahead with results from the first three precincts showing him on 38%, followed by Ron Paul with 23%, Jon Huntsman with 16%, Newt Gingrich with 11% and Rick Santorum on 9%.

Early days! That's three out of 301 precincts.

7.40pm: Who would want to be chair in history at the University of Southern New Hampshire after reading this tweet from a Washington Post blogger?

Oh, not that sort of chair. Carry on.

7.47pm: The Guardian's Stuart Millar reports an "air of anticipation" at the Jon Huntsman watch party in New Hampshire.

7.49pm: Staples ads are currently running on Fox News during its primary coverage – so that's another Super Pac for Romney I suppose.

(Staples was one of the companies funded by Bain Capital while Romney was chief executive, when Romney wasn't between diving into a Scrooge McDuck-style swimming pool full of money from downsizing and outsourcing.)

7.52pm: With 5% of precincts counted, so far President Obama is floundering with a mere 73% of the vote, followed by a candidate named Total Write-Ins with 15%. Somewhere, Obama campaign boss Bill Burton is already giving off-the-record briefings to Politico, saying that Total Write-Ins is "a kook" with ties to Ralph Nader and Dennis Kucinich.

7.58pm: Proof that Mitt Romney is going downhill:

Another win for Buzzfeed Politics. As Butch Cassidy once said: Who are these guys?

8.00pm: As the poll close, Fox News and CNN have called the New Hampshire race for Mitt Romney. Fox is projecting a "significant" win, and that Ron Paul will finished second, and Jon Hunstman third.

Fox News is also calling Rick Perry a big fat loser and finishing last. So as far as Fox is concerned, the big drama is whether Gingrich or Santorum will finish fourth. Seriously.

8.14pm: CNN has some more detail on its exit polls and this is more interesting: according to the exits, Mitt Romney gets 36%. Underwhelming if not awful. Among Republican voters alone Romney got 45% so that's better, in terms of making headway with winning over Republicans grassroots.

8.21pm: The Guardian's Gary Younge emails to ask: "When's the last time a Republican nominee won both Iowa and New Hampshire in a contested campaign?"

According to AP, "A Romney victory would make him the first Republican to sweep the first two contests in a competitive race since Iowa gained the lead-off spot in presidential campaigns in 1976."

But the records show that in 1976, Gerald Ford beat Ronald Reagan in the Iowa caucuses and the New Hampshire primary, so I'm not sure what Romneyesque word play AP means exactly.

Ron Paul in Manchester, New Hampshire. Photograph: Andrew Burton/Getty Images

8.24pm: The slowcoaches at CNN are now also projecting that Ron Paul gets the silver medal and Huntsman comes third, a good 20 minutes after Fox News did the same thing.

8.30pm: So for the second week in a row Rick Santorum is locked in an epic, too-tight-to-call, contest. Except that last time it was with Mitt Romney for first place in Iowa. Tonight it's for fourth place against Newt Gingrich. A week really is a long time in politics.

At the moment Gingrich is ahead by 77 votes. So it's just like Iowa, except that it isn't.

8.40pm: Mitt Romney is on stage now and milking, as you'd expect, veering between Reaganesque shining-cities-on-the-hills and Obama-bashing.

"President Obama wants to put free enterprise on trial and in the last few days we've seen a few desperate Republicans joining forces with him," says Romney, in rather a dull monotone.

Mitt is just giving the Mitt Romney General Election Speech, with plenty of nonsense about Obama being a Euro-socialist. We may be hearing this many many times between now and November, so get used to it.

8.43pm: Interesting point: back in 2008, John McCain won the New Hampshire primary with 38% of the vote. Can Romney beat that?

With 22% of the precincts in, Romney's on 35%, just 10 points ahead of Ron Paul on 25%. If that gap erodes, Romney's victory looks less and less impressive.

8.50pm: The Guardian has correspondents at the results parties of the top three placed candidates. Let's get the mood at all of them, starting with Ewen MacAskill at the Mitt Romney event.

The Romney campaign is celebrating in the dining centre of at a university campus on the outskirts of Manchester. Although it looks noisy and crowded on television – the main purpose for these things – it was strangely subdued, partly because of tight restrictions on entry. The Romney campaign blamed fire marshals for restricting the numbers.

Romney supporters said they were undismayed by the attacks on the candidates in recent days over his time as chief executive at Bain Capital, laying off thousands of workers. Terry Stewart, 53), who runs a small business and lives in Hudson, New Hampshire, was among those denied entry and was heading for home. But it did not dampen her enthusiasm for the candidate.

"I think he is the best person to turn the country round," she said. As for Bain company, she was unconcerned. "This is what business is about. As a small business owner, I know we have to make hard decisions to turn a company round."

Romney as a Mormon does not drink either coffee or alcohol. Journalists, though, had access to both.

9.00pm: The Guardian's Adam Gabbatt is at Ron Paul's watch party, where the mood is jubilant after the exit polls suggest a strong second place for the Republican maverick.

Ron Paul's results party at the Executive Court, near Manchester, is warming up quickly with about 400 people packed into the venue.

A spontaneous chant of "President Paul" broke out just now, with star-spangled banners and Ron Paul paraphernalia being waved aloft – only for a campaign official to ask that the banners be lowered to allow television cameras a view of the stage.

Joan Bastek, 47, was loitering beside the free buffet with a big smile on her face. "This is great," she said, clarifying that he was referring to the atmosphere. "I think he'll do great."

But can he beat Romney? "Yes, I think he can. This is so much better than 2008. I think [the polls] are wrong. They've been wrong before."

Brandon Ashley, 28, was wearing a white Ron Paul baseball cap. "It's gonna be close," he said. "If he doesn't win, there's now a clear movement, and I would consider that a win, people realising that Ron Paul is a viable candidate."

9.10pm: Stuart Millar is in Manchester at the election party of Jon Huntsman, where supporters are in subdued mood following the former ambassador's projected third place.

At Jon Huntsman's packed primary night party in the Black Brimmer pub, Manchester, supporters were struggling to put a brave face on his third place finish. As the result filtered out to the boisterous crowd, a few started chanting "Country first", the Huntsman slogan.

"I'm disappointed and relieved," said Connie from Manchester, who would only give her first name. "A few weeks ago I would have been happy with third, but I had started to think he might come second." But she believes that Huntsman is right to stay in the race. "He absolutely should keep going. He's starting to get traction now, and he wasn't getting it at all before."

Brendan Powers, a 28-year-old history teacher from Peabody, Massachusetts, agreed: "He's the only sane person in the race. He has to keep going, even though he will get crushed in South Carolina. But he's just prepping for 2016 and he'll come back stronger."

He insisted third place in New Hampshire was a decent result: "He's always said he wanted to outperform market expectations and he has done that tonight, even though he's barely managed it."

Powers, who said he had started supporting Huntsman after becoming disillusioned with Barack Obama. But when the inevitable happens and Huntsman drops out, would he vote for Mitt Romney? "I would have to dwell on that," he said.

9.20pm: Ron Paul was talking to a very, very enthusiastic crowd just now. He only has to give the word and Ben Bernanke will be defenestrated.

9.31pm: Ewen MacAskill sums up the mood at Romney party headquarters thus:

Other reporters at the Romney celebrations describe his supporters as "pumped up" and "delirious". And supporters leaving after Romney's speech were declaring themselves to be ecstatic. But to me it did not seem that big a deal, at least not in comparison with the atmosphere at similar Obama victory speeches in 2008.

Here's why Ewen is right to be sceptical: Republican turnout was actually down compared with 2008, suggesting that there isn't a huge groundswell of enthusiasm out there. It may be that Romney actually gets more or less the same number of votes as he got in 2008.

Mitt Romney victory. Photograph: Emmanuel Dunand/AFP/Getty Images

9.39pm: Back to the knife-edge battle between Newt Gingrich and Rick Santorum: with 46% of precincts in, Gingrich is a mere 74 votes ahead of Santorum. So, basically they are tied.

At the top of the table, Romney is stretching his lead. He's now 13 percentage points ahead of Ron Paul, on 37% to Paul's 24%.

9.40pm: Tim Carney of the Washington Examiner uses an apt sports metaphor:

9.43pm: Sarah Palin was on Fox News! Palin is not impressed by Mitt Romney's victory, labelling New Hampshire a "centre-left state":

Not an earth shattering result, I think Ron Paul's showing was a bit of a surprise … I think he's going to shift the debate in the next few days.

Well, Todd Palin came out in support of Newt Gingrich, so maybe Sarah Palin is preparing the ground to … endorse Ron Paul?

But Fox News had to suddenly cut away from Palin to hear third place loser Jon Huntsman flap his jaws.

9.46pm: More from Stuart Millar with the Jon Huntsman crowd in Manchester, where the governor of Utah tried to put a brave face on a disappointing third place.

Huntsman has just finished his speech at his watch party in Manchester and is shaking the hands of his extremely enthusiastic supporters, with his wife and daughters lined up behind him for full televisual effect.

He took the stage just before 9.30pm to cheers of "Country First". His opening line: "Ladies and gentlemen, I think we're in the hunt!" Cue more chanting. Then the main message he's trying to get out tonight: "I'd say third place is a ticket to ride."

Huntsman, who made several references in his speech to the fact that he had lived overseas, told supporters that America faced two problems: the economic deficit – namely $15 trillion of debt – and the trust deficit, in relation to its political leaders.

"The people of this great nation, the greatest nation that ever was, they are tired of being divided," he said. "They want a leadership that will stand up and tell us that we need to come together as Americans in order to solve our problems."

He also got loud applause and a new round of "Country First" chanting for saying it was time to bring the troops home – perhaps recognition of how Paul's anti-war message has resonated with young voters and independents. "Afghanistan is not our future, Iraq is not our future ... If we don't get our act together at home we will see the end of the American century by 2050."

His supporters lapped it up. South Carolina will be harder to convince.

Jon Huntsman, New Hampshire. Photograph: Alex Wong/Getty Images

9.55pm: Mini-drama! Rick Santorum has just overtaken Newt Gingrich in the battle of the losers. With 56% of the precincts counted, Sanotrum has 11,741 votes and Gingrich has 11,726 – a 15 votes margin. It really is like Iowa all over again but not really.

10.01pm: Adam Gabbatt was listening to the speech by runner-up Ron Paul.

"President Paul! President Paul!" rang the chants as the Texas congressman took to the stage here in Manchester, clad in his stock outfit of white shirt, blue sweater and dark blazer.

As the cheering died down, Paul said he had called Mitt Romney earlier to congratulate him, but told the baying crowd: "We're nibbling on his heels."

After he thanked his wife Carol and assorted family members, Paul drew one of the biggest cheers came when he gave special praise to Youth for New Hampshire, who have had a big presence in the granite state and are here
big numbers tonight.

Perhaps aware of his moment in the spotlight, Paul launched into a extended summary of almost his entire political beliefs, lurching from criticism of national debt to defence spending and a well-received pledge to bring troops home.

"America has been the greatest country ever, it's been the wealthiest country ever, it's had the most prosperous middle class ever, but it's n t that way today," Paul said.

The crowd were loud, but perhaps surprisingly given Paul had well outperformed the polls, some had been expecting even more. "Obviously I'm not happy that he didn't win," said Naomi Gilbert, 27. "I was hoping he'd win. But I don't think Mitt Romney will do well in South Carolina."

Nathaniel Blodgett, 18, was happier. "I am very impressed," he said. "I campaigned in Salem, New Hampshire, and want to campaign again in my home state of Massachusetts."

Around half of the crowd left with Paul, but those who remained are being treated to a DJ, currently playing "Celebration" by Kool and the Gang.

Ron Paul speaks to supporters in New Hampshire. Photograph: Andrew Burton/Getty Images

10.06pm: Newt Gingrich and Rick Santorum have both been speaking in the last few minutes. Gingrich acknowledged that the contest in South Carolina would be tough; Rick Santorum – well, Fox News cut away from him to take Gingrich, which just about tells you all you need to know.

Rick Perry (remember him?) is on Fox News, and repeats his earlier attacks on Mitt Romney's credentials at Bain Capital. He draws a distinction between "venture capitalists" (good!) and "vulture capitalists" (bad!) and vows to continue bringing the issue up. He says of Romney:

He's going to have to face up to this some time or another and South Carolina is as good a place to draw the line in the sand as any.

10.20pm: Yahoo News's Chris Moody reports on chaotic scenes at the Gingrich post-match party as Newt starts speaking at the same time as Rick Santorum.

With results in from 70% of the precincts, there are only 38 votes between the two men.

10.30pm: As the picture of the night becomes clear, Ewen MacAskill rates the field.

Rick Santorum: loser
The biggest loser of the night was Rick Santorum, unable to capitalise on his late surge in Iowa that brought him to within eight votes of Romney just a week ago. Santorum was the man of the moment then, followed around by the media hordes, attracting big crowds to his meeting curious to see the man who almost beat Romney. He needed to maintain the momentum from Iowa with at least a top three finish and that was denied him.It is possible he could enjoy a revival in South Carolina, where the north-west of the state will be receptive to his anti-gay, traditional family values rhetoric. But the southern part round Charleston will be less receptive. Even Mike Huckabee, who actually won Iowa and won well, could not take South Carolina. So it may turn out that Iowa was Santorum's high point.

Ron Paul: winner
It was a strong second place for a candidate who has for so long been on the margins of US politics. His campaign team does not expect to win the nomination but he can keep the race going for months, building up a bloc of delegates to take to the Republican convention in Florida in August, where the nominee is formally chosen.

Jon Huntsman: loser
A disappointment for a candidate who staked everything on New Hampshire. He needed a second place finish and did not get it. His mixed messages – he presents himself as both the most moderate and the most conservative – did not do the trick in New Hampshire and there is even less chance in South Carolina. He had little organisation or money in New Hampshire, and even less in South Carolina. He could quit after South Carolina or maybe after the fourth of the contests, Florida.

Mitt Romney: winner
History says no candidate has won the nomination after losing Iowa and New Hampshire. So history seems to be on Romney's side. But South Carolina politics can be brutal and he only took 15% there in 2008. If he loses South Carolina, his route to the nomination is no longer smooth. A loss in South Carolina – and Florida, instead of a relatively easy win for Romney, becomes a toss-up state.

Newt Gingrich: loser
Gingrich, high in the polls in New Hampshire in December, has been slowly deflating. But he could come back in South Carolina. He is liked there, at least in the southern part of the state. More importantly, smarting from the multi-million Romney ad campaign against him in Iowa, he is on a mission to destroy and there is only one target: Romney. It promises to be nasty, which Gingrich does well.

Rick Perry: loser
Perry, who did not compete in New Hampshire, sent out a statement saying he had a head start in South Carolina. He has been a joke candidate so far, managing to make George W Bush look polished by comparison. But he still has the money and staff to make an impact. A long shot but South Carolina likes southerners.

10.45pm: So there wasn't any drama out of the New Hampshire primary: the guy that we thought would win, won, and won by the sort of margin that the polls suggested he would.

Even if his final vote total didn't overwhelm any of his rivals with shock and awe, Mitt Romney leaves New Hampshire in a strong position because the rest of the field still hasn't settled on a single anti-Romney candidate.

The second and third place holders in New Hampshire, Ron Paul and Jon Huntsman, will hardly figure in South Carolina. That leaves Romney having to contend with the pygmies who finished well down in New Hampshire, Gingrich, Santorum and Perry, all bickering over over the same end of the electoral spectrum.

Back in 2008, in a similar position, John McCain ended the Republican contest when he came through a South Carolina field divided by Mike Huckabee and Fred Thompson splitting the conservative vote. From where I'm sitting, it looks like we are in for a repeat in 2012.

So once again, as it did in 2000 and 2008, South Carolina is where it all happens: a bedrock conservative piece of the Republican heartland. If you can win it there, you can win it anywhere, it's up to you, Mitt Romney, Mitt Romney.

There are some results still to come in, but we're calling it a night there. Thanks for reading and for your comments, and we'll be back with a live blog tomorrow.