The rapidity of the slide is due to the Wall Street bailout. Instead of punishment of the perps, we are getting bonuses. Instead of reform to prevent gambling, we get more of the same (even worse, it is being done with an explicit government backstop). Instead of relief for the middle class we get profiteering as the financial industry extracts everything they can from a tapped populace.
Nothing could have eroded trust faster than this. All agenda items after this fiasco are/were forfeit.
This is the opposite of what FDR did when faced with another economic crisis. He created massive numbers of jobs, new safety nets, and quite deliberately went against his own class and taxed them hard. And was one of the most popular presidents in history.
However a new Gallup Tracking Poll shows Obama gaining for the first time in a while. I expect a major push on multiple fronts will come out of the White House after Labor Day is over.