America's next president odds - Can anyone defeat Hillary Clinton?

Elizabeth Warren (9.00 with Betfair at time of writing) might be unwilling to oppose Clinton but ex-Maryland governor Martin O’Malley (13.00) could be the breath of fresh air candidate in 2016.

Hillary Clinton 2.20 is the favourite to be America's next president but the contest to be her opponent is wide open. Jeb Bush has taken his time before officially declaring his candidacy for the Republican Party nomination but he's been the favourite on Betfair since December when he said he would "actively explore" a run for the White House.

Bush, who's 3.40 to be Republican nominee, isn't the only candidate who's been coy so far. One of his principal rivals, Wisconsin Governor Scott Walker 5.20, is yet to formally throw his hat into the ring, but both men have assembled teams which are busy canvassing supporters and soliciting campaign funds. Likewise Florida Senator Marco Rubio 5.10 who's currently Bush's nearest rival in the betting.

The strongest indication so far that Bush will try to emulate his brother and father by becoming president came when he vowed to "campaign hard" to win the support of Republican activists in Iowa. The Iowa caucuses are often crucial in determining who will be the nominees for both the Republican and Democratic parties. In 2008, for example, Barack Obama's campaign gathered momentum when he unexpectedly defeated Clinton in Iowa, went on to win his party's nomination and the presidency. If Bush loses to Rubio or Walker in Iowa next February, he'll have problems.

Elsewhere, there are familiar names among the Republican hopefuls. Rick Santorum, the former-senator for Pennsylvania, is running but bettors make him 75.00. Those are long odds for a man who unexpectedly finished second to Mitt Romney in 2012. Rick Perry (46.00), meanwhile, looks like one to avoid, as he attempts to succeed where he failed four years ago.

Mike Huckabee (18.00), who ran in 2008, is also giving it another go and Rand Paul (11.50), whose father Ron won support from the Republicans' libertarian wing four years ago, could play a big part in the contest. Among the Republican newcomers, keep an eye on Ted Cruz and Ben Carson, both 30.00.

Bush's greatest asset is also his biggest potential problem. Among Republicans, his surname gives him instant gravitas but, to swathes of voters in the political centre, his association with his brother will be off-putting. Bush didn't help matters when he recently said that he thought invading Iraq was the right thing for America to do under President George W. Bush.

Ever since she lost to Obama in 2008, it's been argued that Clinton can win in 2016. But surely her defeat eight years ago means we can't, with any confidence, predict that Clinton will succeed in winning the nomination, let alone the presidency, this time? Elizabeth Warren (9.00) appears unwilling to fight Clinton for the nomination but ex-Maryland governor Martin O'Malley (13.00), who has none of the sleazy associations that could dog both Clinton and Bush, is going to run and he might be 2016's breath of fresh air candidate.

With 18 months to go until America votes for Obama's successor, there isn't an array of formidable candidates to oppose the front runners in either party. However, there's plenty of time for somebody to emerge in the manner that Obama did in 2008 and, as Bush's Iraq war comments and Clinton's rumbling email controversy indicate, skeletons could yet emerge from their closets. Bush may have to pay for his brother's mistakes while the person who will ultimately be responsible for Clinton's downfall could be Clinton herself...