Mitt Romney’s preferred argument, however, is stewardship. Are you better off today than you were $5 trillion ago? Look at the wreckage around you. This presidency is a failure. I’m a successful businessman. I know how to fix things. Elect me, etc. etc.

Easy peasy, but highly risky. If you run against Obama’s performance in contrast to your own competence, you stake your case on persona. Is that how you want to compete against an opponent who is not just more likable and immeasurably cooler but spending millions to paint you as an unfeeling, out-of-touch, job-killing, private-equity plutocrat?

The ideological case, on the other hand, is not just appealing to a center-right country with twice as many conservatives as liberals, it is also explanatory. It underpins the stewardship argument. Obama’s ideology — and the program that followed — explains the failure of these four years.