So far, no candidate has made a strong case for being a likely runner against Barack Obama later this year.
Republicans at the starting line - in a race out of control
The 2012 US election season begins tomorrow when Iowa becomes the first state to hold contests to decide who will be the Republican presidential candidate in November. While Barack Obama will be renominated as the Democratic contender, the Republican race's outcome is uncertain.
In November and early December, Newt Gingrich surged in national opinion surveys of Republican identifiers. Although this lead has narrowed considerably in recent weeks, and indeed some national surveys show him trailing or in a statistical dead heat with Mitt Romney, it should be remembered that Mr Gingrich had been almost completely written off as a candidate only a few weeks before.
But can the controversial ex-leader of the House of Representatives really become the Republican nominee, and then beat Mr Obama in November 2012?
On the first of these questions, Mr Gingrich is not the favourite, but he does - at least for now - have an outside possibility of becoming the nominee, especially if he performs better than anticipated in early state nomination contests. The last few decades of US political history indicate that the victor in presidential nomination contests usually leads national polls on the eve of the Iowa ballot (traditionally the first nomination contest), and also raises more campaign finance funds than any other candidate in the 12 months before the election.
From 1980 to 2000, for instance, the eventual nominee in eight of the 10 Democratic and Republican nomination races that were contested was the early front-runner in the polls and fund-raising. This was true of George W Bush, the Republican candidate in 2000; Al Gore, the Democratic nominee in 2000; Bob Dole, the Republican candidate in 1996; Bill Clinton, the Democratic nominee in 1992; George HW Bush, the Republican candidate in 1988 and 1992; Walter Mondale, the Democratic nominee in 1984; and Jimmy Carter, the Democratic candidate in 1980.
Seen through this polling and fund-raising prism, the 2012 Republican race resembles the 1980 Republican and 1988 Democratic contests. As Iowa approaches, no single candidate clearly leads the field on both measures that signal early front-runner status. Mr Romney raised the most money of any Republican candidate in 2011, while the lead in national polls that Mr Gingrich had enjoyed since November has narrowed considerably.
So who is best placed to win?
Predictions are always difficult. However, at this stage it seems most likely that Mr Romney will prevail, possibly with ease. His campaign not only has superior financing, but also a much better national organisation as evidenced by Mr Romney's recent success in securing 10,000 signatures to get on the Republican nomination ballot in Virgina, and Mr Gingrich's failure to do so. Nonetheless, Mr Gingrich still has a chance if he wins big in Iowa tomorrow.
Other candidates (including Rick Perry, Rick Santorum and Ron Paul, who has led the Republican field in some recent state polls in Iowa) are also still in the running. It should be remembered that Mr Obama, John McCain in 2008 and John Kerry in 2004 were all behind in the polls or fund-raising before Iowa. Mr Obama was in Hillary Clinton's shadow for much of the year before the 2008 election season began.
Whichever candidate wins the nomination, one of the key factors that will influence Republican prospects to defeat Mr Obama will be whether, and how quickly, the party can unite around the nominee. A model for Republicans is the 2000 cycle when Mr Bush emerged strongly from a wide field of contenders before going on to defeat, controversially, the Democratic candidate Mr Gore in November.
However, it may be harder for any of these candidates to unify the party. Mr Romney hit a relatively low national ceiling of support at around 25 per cent of Republicans. This is largely because his generally moderate conservative views (which make him more electable than Mr Gingrich in a national election) have alienated a significant group of right-wing Republicans, including many of those with Tea Party sympathies.
By contrast, Mr Gingrich is generally perceived as a maverick by the Republican establishment, which has considerable doubts about his electability against Mr Obama. Moreover, Mr Gingrich's support from right-wing Republicans in national polls could also prove very fickle as they have concerns about his perceived ethical wrongdoing.
Most Republican operatives are keen to avoid a bruising, introspective and drawn-out contest which exposes significant party divisions. The last time such a scenario unfolded for Republicans, in 1992, the chief beneficiary was Democrat Bill Clinton who won a relatively comfortable victory.
While the circumstances of 2012 are different from 1992, another divisive Republican contest would almost certainly provide a boost for the Obama campaign's fortunes. With the president's job approval ratings at or below 45 per cent, historically low for an incumbent seeking re-election, he remains vulnerable.
Indeed, Mr Obama's re-election prospects may now rest to a very significant degree on a factor that remains out of his hands. That is, whether the US economy can stage a significant recovery in 2012 at a time when other areas of the world, including Europe, appear to be heading back into recession.
Andrew Hammond is an associate partner at ReputationInc and a former special adviser to then-prime minister Tony Blair