I think this can be tied, at least indirectly, to the surge in conservatism, renewed faith in the free market, and the likelihood that a new Congress will keep or revive the Bush Tax cuts.
If the tax cuts pass and Barry vetoes them, I submit that his chances for reelection will be diminished considerably, even worse than his prospects are now.
The DemonRATS are stuck with the narcissistic Marxist. If they overthrow him in their primary, they lose. If they run him they lose.
The only thing they can do is distance themselves from him on the local level. But it may be too late for that after all the swooning local pols did for him in 2008-2009.
But the average of 3 surveys (Concensus, AAII, and Market Vane) are still below the peak of 61 set April 16 this year and the peak of 69 set in October 2007.