What Obama Should Do Next The last time I considered Barack Obama's re-election chances in this magazine, in mid-November, things were looking pretty bleak for the president. The statistical model I used measured three key factors - a president's approval rating, economic growth and the ideological orientation of his opponent - and taken together, they showed that Obama had become a slight underdog to win re-election. Three months later, his position is much stronger. In January, 243,000 jobs were created. The number surprised investors and economists, but it was part of a stream of solid economic data: over the last few months, consumer confidence has gone up, Americans have spent more on big-ticket items like cars and there is even evidence that the housing market has begun to rebound. Before the job numbers came out, most economists were expecting around 2.5 percent G.D.P. growth this year. Those forecasts are liable to be revised upward now, perhaps to about 3 percent. Americans seem to have noticed the change. By early February, Obama's approval rating had climbed to 49 percent in the Real Clear Politics average, a six-point improvement from three months earlier. Although it's not a terrific approval rating, it may be enough to get Obama another term. In 2004, George W. Bush won a narrow victory with essentially identical metrics: G.D.P. growth of 2.9 percent and an approval rating of about 48 percent on Election Day. Still, Obama's position isn't solid enough for him to beat just anybody. Bush benefited from running against a middling opponent like John Kerry, against whom he was able to squeeze every ounce out of his approval rating. The model I created evaluates the strength of the opposition candidate by considering his ideology on a left-to-right scale. Candidates who are closer to the center have historically done better than those closer to the wings. I've updated the model's measure of ideology to account for new data. Obama's most likely Republican opponent, Mitt Romney, continues to rate as a "generic Republican." In fact, he now scores at exactly 50 on the 100-point scale from centrist to extremist. That means an election against Romney, like Bush's against Kerry, would mostly be dictated by the fundamentals of the economy and by evaluations of Obama's job performance. With 2.5 percent G.D.P. growth from now through November, Obama would be a 60 percent favorite to win the popular vote. The popular vote is one thing, however. The Electoral College is another - and Romney could have more vulnerabilities there. In recent weeks, Obama has taken a more populist approach (just read the transcript of his State of the Union address). The strategy has induced more howls than usual from Republicans about "class warfare," but the White House has clearly studied the numbers. In the Republican primaries, Romney has had trouble winning the loyalty of working-class voters, especially in the Midwest. And recent polls suggest that Romney, who has a penchant for making intemperate comments that draw attention to his wealth, could struggle among that group in the general election as well. So let's conduct a thought experiment. Suppose that against Romney, Obama does 10 points better among white voters whose households make less than $50,000 per year. The trade-off is that he does 10 points worse among whites making $100,000 or more and 15 points worse among whites making at least $200,000. In terms of the popular vote, this would almost exactly balance out. The effect would be more substantial, however, in individual states. In wealthy Virginia, Obama would lose a net of 2.5 percentage points to Romney under these rules, according to the demographics from the 2008 exit poll there. He would also be harmed by 2.7 points in Colorado. And Romney would have a chance of putting New Jersey into play, because he would gain four full points there. The Chris-Christie-for-V.P. train will be departing from Platform 1.