There are lot pitfalls facing an incumbent presiding over a struggling economy but if you're interested in his re-election plan then have a look at this nakedly political video by Jim Messina, the Obama 2012 campaign manager (and excuse the bizarre moment of swearing):
17.50 (11.50) The American broadcast media has a fascinating relationship with Ron Paul. The major news channels acknowledge that he's a serious candidate and faithfully report his growning popularity but they simply cannot stay interested in what he's saying.
CNN was just covering one of his rallies in Des Moines but as soon as he began in his familiar riff about personal liberty they cut away. As he predicted, Paul got big cheers when he said that 70 per cent of Americans support ending the war in Afghanistan and bringing the troops home.
17.38 (11.38) There will be a flurry of polls over the next 24 hours but here's the most recent from Insider Advantage, which surveyed 729 likely voters yesterday.
It shows Romney and Paul in a statistical dead heat but with Santorum closing in behind. Interestingly, the poll also finds that Paul has a huge advantage amon independents, a traditional Romney strong point. Around 38 per cent of the Indies went to Paul, compared to only 18 per cent for Romney.
17.25 (11.25) Our own Alex Spillius has written this useful guide explaining how the caucus system works.
In Iowa today, voters will arrive at 7pm at 1,774 locations across the state including schools, libraries, hotel meeting rooms and even people’s homes to cast their vote for the Republican presidential candidate. The numbers at any location will vary between a handful and several dozen.
A caucus is a small political meeting, which begins with someone being chosen to chair proceedings. Local supporters of candidates then argue their case for a few minutes before votes are cast. A north American peculiarity, the provenance of the word is disputed.
Unlike primary and general elections, where larger polling stations are open all day, the meetings last about an hour. Votes are then counted on the spot and are phoned in to county officials.
Voters write their choice on a bit of paper or tick a name on a more conventional-looking printed sheet and drop it in a box — sometimes a shoebox or cardboard box. Voters are not limited to choosing official candidates. One Republican official said: “You could vote for your granny if you wanted to.” Anyone can vote in the Iowa Republican caucus, as long as they are an adult resident in the state and have valid identification.
17.16 (11.16) Ron Paul is on CNN with his son, Senator Rand Paul. The generations of Pauls have just landed a one-two punch on Santorum, with the older man describing him as "very liberal".
Look at his record. He's spending too much money. He wasn't leading the charge to slash the budget or roll back big government.
Paul Snr is in his trademark ill-fitting suit while his son wears a more casual cardigan. Both staunchly defend their campaign's foreign policy positions of non-intervention and withdrawing American forces around the world. "When I talk about the war you will hear the loudest cheers," he says.
17.10 (11.10) There is absolutely nowhere to hide in the Hawkeye State if you're trying to escape from a handshaking presidential wannabe. Have a look at the Politico daily calendar to get a sense of the pace of campaigning going on. Most candidates have at least five events today.
17.05 (11.05) Jon Swaine tweets this picture of Santorum leaving the Reising Sun coffee shop in Polk. The candidates says "We're seeing momentum and intensity" as he predicts a top-three finish.
16.55 (10.55) As the day begins to warm up politically in Iowa (temperatures are still below freezing) let's take a quick review of the candidates and where they stand:
Mitt Romney, former Massachusetts governor, 23 per cent.
The race's slow-but-steady frontrunner is looking confident with just under 36 hours to go until polls open in Iowa. A win here followed by a crushing victory in New Hampshire could give Romney an unassailable lead.
Ron Paul, Texas congressman, 22 per cent
The Libertarian has had a rough two weeks following the emergence of racist newsletters that he published in the 1980s and 1990s but his core support is holding strong and he's statistically tied with Romney. If the weather is bad tomorrow his devoted loyalists could storm to victory.
Rick Santorum, former Pennsylvania Senator, 16 per cent
Santorum has been ignored for most of the campaign but today is threatening an astonishing upset in Iowa. He is successfully rallying both Evangelicals and conservatives and may finally by the anti-Romney so many in the GOP are waiting for.
Newt Gingrich, former speaker of the House, 14 per cent.
Has been hit by waves and waves of negative advertising that have dragged his poll numbers from the low 30s to the low teens in just a month. Gingrich has admitted he isn't going to win but has vowed to stay the course in the hope of redemption in South Carolina and Florida.
Rick Perry, governor of Texas, 12 per cent
Perry's camp is watching in despair as Rick Santorum gathers up the Evangelical vote. The former Air Force pilot is the biggest spender on TV air time in the tiny state but is struggling to avoid to stay out of the bottom three.
Michele Bachmann, Minnesota congresswoman, 7 per cent
Bachmann was born in Iowa, is a ferocious conservative and over the summer enjoyed a strong lead for several weeks. Now she is looking down the barrel of a last-place finish which would probably end her candidacy.
Jon Huntsman, former governor of Utah, 2 per cent
The former ambassador to China is not competing in Iowa and is placing all his hopes in New Hampshire. Expect him to finish dead last tomorrow.
16.32 (10.32) Gingrich has just admitted that he's not going to win the caucuses tomorrow
I don't think I'm going to win. Those negative negative ads have done enough damage.
He repeatedly cites the $3.5m of negative ads aimed at him but says that the people of Iowa are beginning to see through them and reminds reporters that around 40 per cent of caucus goers say they could still change their minds.
16.23 (10.23 in Iowa) In a freezing Polk City Rick Santorum has been fielding questions on everything from bipartisanship to Syria to the environment. On that last topic he rails against the Obama administration's green regulations, which he says are the result of a hatred of carbon and blue collar workers. One of the most interesting moments is when he's asked if he has the funding and the organisation to defeat Obama's lethal re-election campaign. "We've raised more in the last few weeks than we have in the last few months, he says. Our own Jon Swaine has been talking to some of the people at the event.
Jim-Bob Duggar , a televangelist from northwest Arkansas, has driven through the night with 12 of his 19 children, his mother and his sister, to be here backing Mr Santorum. "We are calling on Christian conservatives around the country to come together and send Rick to the White House," he told The Daily Telegraph. Right-wingers need to be aware that Mitt Romney made it easier for teenage girls to obtain abortions as Governor of Massachusetts, he said.
15.42 A last minute blitz of campaigning is expected today, before Iowans cast the first votes of what will be a year-long fight to the November 2012 elections. Mitt Romney has made little secret that he hopes a first- or second-place showing in Iowa, followed by a win in New Hampshire one week later, and another in South Carolina after that, will let him win the nomination relatively early and focus his energies on taking on Barack Obama for the White House.
15.11 A Telegraph video of Mitt Romney saying he is "encouraged" by Iowa support:
14.45 Several candidate have surged up the Republican field and then dropped back down, notably Michele Bachmann, Rick Perry and Herman Cain. Newt Gingrich is the latest to apparently run out of puff, to be displaced by the ultra-Right-wing former Pennsylvania Senator Rick Santorum, who, until last week, was relatively unknown. Here, Jon Swaine looks at his late run up the ranks:
Mr Santorum, who has spent three months travelling the state in a pickup truck and without any staff, has become the latest alternative to Mitt Romney to rise sharply in the opinion polls.
Having been stuck in low single-digits throughout the campaign, he came third behind Mr Romney and Ron Paul in the final Des Moines Register poll, backed by 15 per cent of likely caucus-goers.
However the 53-year-old, who is supported by many evangelical Christians for his zero-tolerance stance on abortion, overtook Dr Paul when the last two days of the four-day survey was considered separately.
Republican presidential candidate Rick Santorum campaigns at the Smokey Row Coffeehouse in Oskaloosa, Iowa
14.32 From Bill Clinton to John Boehner, American politicians are known for welling up. Here is a Telegraph video of Newt Gingrich brought to tears talking about his late mother, while Mitt Romney compares President Obama's comments on the economy to Marie Antoinette's famous "let them eat cake" remark:
Gingrich was speaking to a bipartisan group of 100 Iowa mothers as he recalled childhood memories of his mother Kit Gingrich, who died in 2003 at the age of 77.
"I get teary eyed every time we sing Christmas carols. Excuse me. My mother sang in a choir and loved singing in a choir. And I don't know if I should admit this, when I was very young, she made me sing in the choir," Gingrich said.
14.24 Frontrunner Mitt Romney tweeted last night:
14.19 An even number of voters want a candidate who shares their values as want a candidate who can beat Barack Obama, according to an NBC/Marist poll. Matt Strawn, Iowa Republican Chairman, said:
The first thing you see when you talk to any Iowa Republican is that desire to beat Barack Obama.
14.10 Newt Gingrich, who recently enjoyed a surge in the polls but who has faded just as fast, has been trying to recapture voters late in the day. In an interview with Reuters, he attacked Romney, while attempting to emphasise that he doesn't criticise his rivals as part of his "positive" campaign:
By the time we get to South Carolina, it will be very clear the gap between a Massachusetts moderate who hides his record behind negative ads and a conservative who's talking about positive ideas.
As major donors in this country realise how much Mitt Romney's not going to defend them and not going to protect them and not going to help them, that he will face a lot bigger challenge than I will.
13.02 Speaking on Monday night, Mitt Romney made an eleventh-hour pitch to Iowa voters:
I can't tell you who's going to win this thing. But I do believe that I'm going to have a great deal of support and that that will give me the kind of boost I need as I go into a season of (contests in) a number of other states. This is a process that begins here.
12.23 Jon Swaine's story from this morning's Telegraph on how Mitt Romney could pull off a historic double victory in Iowa and New Hampshire:
The former Massachusetts governor leads the party field both in Iowa, where tomorrow’s caucuses will give the candidates their first test, and in New Hampshire, where voters go to the polls next Tuesday.
If successful, Mr Romney would become the first Republican challenger in the modern primary system’s 35-year history to win both states. Party strategists concede that such a scenario would effectively end the contest after just one week of voting.
12.00 (0600 CST) Good afternoon - or morning to our US readers - and welcome to our live rolling coverage of the 2012 Iowa Republican primary.
So far the Republican elections have already been tumultuous with rumoured sex scandals, embarrassing gaffes and cries of racism, witchcraft and cronyism, and the polls haven't even opened. Now, with 24 hours to go before the first caucuses open in Iowa on Tuesday, Americans will finally have their chance to give their verdict on the Republican candidates still in the running to face Barack Obama in the 2012 presidential election.
Mitt Romney, the former Massachusetts governor, is perhaps the favourite in the race having consistently faired well in the GOP debates in the run up to the polls. He is now on course for a historic double victory.
Rick Perry, the Texas governor, was an early favourite but fell down after one of the most excruciating 53-seconds in a televised debate since John F Kennedy clashed with Richard Nixon in 1960. Here is that "oops" moment again for those who may have missed it the first time.
Herman Cain, of Godfather's pizza fame, grasped the lead from Perry following the gaffe, only to fall down himself after a string of allegations about lurid affairs with several women. Despite enjoying a significant lead in the straw-polls, Cain dramatically suspended his campaign.
Newt Gingrich, the former House Speaker, was given a surprise boost in the Republican race after Herman Cain pulled out but was weakened by claims that he was paid up to $1.8 million (£1.14 million) for advising Freddie Mac at the height of the financial crisis. He was also hit by allegations that he divorced two of his wives while they were suffering from cancer and multiple scerosis respectively.
The candidates still in the race include:
Mitt Romney, former governor of Massachusetts
Ron Paul, US representative for Texas's 14th district
Michele Bachmann, US representative for Minnesota's 6th district
Jon Huntsman, former governor of Utah and US ambassador to China
Rick Santorum, former US senator for Pennsylvania
Rick Perry, governor of Texas
Newt Gingrich, former Speaker of the House
Those who have withdrawn include:
Herman Cain, businessman
Tim Pawlenty, former governor of Minnesota
Gary Johnson, former governor of New Mexico
Here is our team covering the US elections: