Bush had a 80%+ at one time as well...
Bush needed 911 and the Iraq War to get that high.
Obama needs his "Economic Depression Catastrophe" and the Bush administration to maintain his.
No need for Bush any more. People see Obama speak and are so relieved to see somebody that seems to be on top of things and can speak English really well. Appearance is everything. If the economy tanks even more, people will take it out on Obama. And then Obama's folks will blame it on the Rs for forcing so many cuts from the stimulus bill and say that it was neutered. And so on.
For Obama to maintain these ratings, the economy is going to have to improve and jobs need to be created. From what I have read, he's going to get that in the short run. But the real test will be in the late summer and early fall. Or so I have read/heard from folks like CA Fitts and Celente.
Appearance, marketing and merchandising the "brand" are all in play in this age of American Idol. Just like Idol tries to take an average to below average singer, dress them up, coach them up and then just continually pound it into the public that these people are the greastest, so too I believe, we have seen in the political arena.
Obama may speak well when reading a speech or with reponses to lame setup questions, but, shooting from the hip he stumbles all over himself. Not that we get that many chances to see those situations, just like most Americans didn't know FDR was in a wheelchair at the time.
I have this feeling that we are being set up for when the economy does fall even further, they'll just say that we didn't "stimulate" enough. I don't see how he is going to get that short term bump with so much of this spending coming in the second, third and fourth years.