Here's the month-by-month chart for Obama's "approval index" (strong approval minus strong disapproval) from Rasmussen:
Since the momentary bump upward when Osama bin Laden was killed in May, the trajectory for Obama's approval rating has been down, down, down, with the month of August showing a steep drop of 4%. If September and October continue this trend, I would expect some rumblings from old-guard Democrats for a primary challenge. I don't expect that ultimately they'll be a primary challenge -- the Democrats can't risk offending the black community by running against the first black President -- but there will at least be some serious talk.
Man, I can't wait for the tell-all books coming out of this administration.
But mostly I just can't wait for November 2012.