US Presidential Debate: Betfair markets say this is it for Mitt

If Mitt keeps the talk domestic, he might be able to score a few points off Obama

With Barack Obama's odds seeming to shorten by the day Mitt Romney needs a game-changer, says Mike Robb, ahead of the first US Presidential Debate...

On the eve of the opening live presidential debate, Mitt Romney is in a hole. With Barack Obama trading at 1.251/4, an implied 80 per cent chance, the Betfair market tells much of the story. If he is going to be in-play on Election Day in a little over four weeks' time he needs a game-changer, and this debate needs to be it.

All this fighting talk sounds well and good, and Romney will no doubt have been preparing for the debate around the clock. But all this is somewhat trivial when you remember what you are up against: someone with a healthy lead in the polls, one of the finest orators ever to hold the office of president, and someone who connects with voters more than any president in a long time, perhaps ever.

Romney needs to realise he is not going to win the personality stakes. I can't think of a politician on the planet - let alone within the Republican Party - who would. He needs to make it about policy, and pick apart the mistakes Obama has made, the lack of progress on the economy, and any failed promises from his 2008 campaign.

The first of three debates between now and October 22, this opener is focused on domestic issues, which is a saving grace for Romney as he is certainly strongest on this ground. He has huge business experience to flout in Obama's face; a couple of policy issues that will certainly connect with his target electorate, none more so than the polarising Obamacare; and, ultimately, Romney is weak when we start talking about events beyond US borders. Weak, in all truth, is perhaps being kind. He has shown himself to be an outright liability.

So can Mitt turn it around in this debate and make the race back into something that resembles a contest? It is going to take a huge effort, but ultimately it must come now. If Obama is not at longer odds than the 1.251/4 available right now come 3am GMT, this race is over.

Which, of course, doesn't answer the question as to whether or not he'll do it. Given the topic, the absolute need for a performance, and the fact that Romney is a man certainly capable of winning it, I'm half tempted to lay Obama and look for a small trade after the event. But perhaps this is heart over head: part of me wants Romney to win this debate just so that, from a betting perspective, we have something to play with over the next month.

Because if he doesn't perform, this race is over.

The first US Presidential debate takes place from 9pm EST (2am in the UK) tonight, and will be shown live on BBC News.