Look at this chart of Obama's approval on the economy going back over the course of his presidency. A lot of wobblies. But if you look closely it goes from negative to really negative right as the debt limit crisis started to heat up early last summer.
Now why was this so? Many interrelated reasons. But I think it was a mix of a) a general (and painfully accurate) public perception among the public at-large that no one was at the helm of the ship of state or national economy and b) a general public disgust that just everyone in Washington couldn't get their act together. If you were watching closely, it was pretty clear that it was a hostage-taking situation on the Republicans' part. But loosely affiliated voters, by definition, aren't looking that closely.
What you see on the chart is that after the debt crisis gets settled Obama's numbers start to improve. Not a lot. But a significant enough amount to get them back to their pre-summer 2011 baseline. Certainly the quickening pace of job creation in the late 2011 and early 2012 helped that too. But I think this political factor was also a big -- and clearly dominant at the start of it.
Now, this doesn't dispute or undermine Steve's point. But it qualifies or contextualizes it in a certain way. The shift's in the public's evaluation of Obama on the economy has been tied as much to political changes as to data on the economy itself. And that may be indicative of the future as well.