Then in early 2011 it veered into really bad territory and peaked around the time of the debt limit debacle. From the summer into the late Fall the president's approval on this critical metric dipped deep into the 30s and his disapproval numbers were consistently at or above 60%. That's extremely dangerous territory for a sitting president.
But starting about three months ago those numbers started to improve substantially. The Romney campaign knows that if those numbers get back near even or actually go into positive territory, Romney's probably sunk in the general.