Mitt Romney is close to wrapping up the Republican presidential nomination. If he wins in South Carolina, where he has an eight-point lead over Newt Gingrich, he's essentially proved he can win anywhere and the party elite will move to bring everyone behind the presumptive candidate. The opposition to Romney from the right has been disorganised, unable to pick a pretender and stick with him. Failing to squish Ron Paul is one thing, but still having Gingrich and Rick Santorum squabble over true-conservative votes shows poor judgement. Gingrich has been reduced to going negative on Romney, yet evangelical endorsements are still going to Google-bombed Santorum. Democrats must be hoping for an unlikely upset in South Carolina or Florida to keep the race alive.

More likely, Romney will wrap it up quickly and it'll be time to handicap his matchup with Obama more precisely. Neither is especially popular compared to recent nominees, with favourable and unfavourable ratings roughly matched. In a referendum-style election, this would look worse for the incumbent. The betting markets, however, give Obama a slight edge, which might seem counter-intuitive -- especially with a stagnant economy. It's not just the current economy that explains election results, however, it's also the improvement in the economy over the term, which helps out governments around the world that camne to power just after the financial crisis.

The presidential race currently looks like it will be tighter than the battles for Senate and House control. The Republicans have a huge structural advantage in the year's Senate races, and it will be surprising if they don't pick up a majority. In the House, the Democrats have a fighting chance, but they have a huge deficit to make up in an incumbent-friendly system. Their best chance will be if Obama has a clear advantage over Romney on election day, and brings in a bunch of Democrats on his coattails. While the US left's love affair with Obama is on the rocks, he remains their best avenue for electoral success.