Two weeks into 2012, Romney has a new message: don’t give Obama credit for making the economy better. In effect, the Republican is arguing, “Sure, Obama inherited a deep recession. And sure, he took a bunch of steps to turn the economy around. And sure, we’re now seeing more jobs being created and more economic growth. But vote against him anyway.”

This isn’t just a tough sell; it’s an impossible one.

Look again at what Romney said in last weekend’s debate: “The president is going to try to take responsibility for things getting better. It’s like the rooster trying to take responsibility for the sun rising.”

By Romney’s own reasoning, the sun is rising and it’s morning in America. As Jon Chait put it, “This seems like a shockingly weak line — if you concede that it’s morning, you’ve lost the argument.”