Obama breaks clear

The rejuvenation of Barack Obama’s re-election hopes continues apace. He’s added seven points to his approval rating since November, improving it from the low 40s to around 50 per cent now. After months of polling neck-and-neck with Mitt Romney, he now boasts a six point lead. Just four months ago, the bookies thought he was more likely to lose the election than win it. Now Intrade gives him a 60 per cent chance of victory.

Nate Silver has a great article on Obama’s chances in this week’s New York Times Magazine. He’s built a model to forecast the election results based on the three most important factors at this stage: Obama’s approval rating, his opponent’s ideology and economic growth. You can play with an interactive version of it here: just plug in your prediction for US GDP growth and see how likely each of the four Republican candidates is to beat Obama.

Setting growth at 2.5 per cent (the current forecast of the Wall Street Journal’s economics panel) makes Obama the 60-40 favourite against Romney. When Silver first launched his model back in November, and Obama’s approval rating was 43 per cent and growth was forecast at 2.3 per cent, it made Romney the 60-40 favourite.

And then, of course, there’s the possibility that Obama won’t be facing Romney in November at all, but rather a different Republican candidate — most likely Rick Santorum. The conventional wisdom has always been that Romney is the man with the best shot at beating Obama. But since Santorum’s recent surge, some polls have shown him doing slightly better against the President than Romney. This has led some to suggest that Romney might not have an electability edge after all.

But, as Nate Silver points out, head-to-head polling isn’t very reliable this far out from election day. A much better indicator of electability is a candidate’s ideology, which his forecasts do take into account. And that makes Santorum — further to the right than Romney — a far less troubling opponent for Obama. Silver’s model gives him just a 23 per cent chance of victory if he’s the nominee.