I never met George W. Bush and have no opinion on his intelligence or lack thereof. But it seems to me that conservatives ought to hope he was the knuckledragging moron of Saturday Night Live caricature rather than the cunning super-genius that Keith Hennessey has portrayed. After all, one way or another his term in office was a disastrous period of American governance.
One possible explanation for that would be that he's dumb. Or alternatively that he's incredibly lazy. The president of the United States has a tough job, after all, and it's totally possible to imagine a person with roughly correct ideas to nonetheless screw it up through incompetence and blundering. But if conservatives want us to believe that the United States blundered through a major terrorist attack, two major failed military adventures, dismal economic performance, and then finally an epic economic collpase all while under the watch of a very bright and attentive leader then it seems like a much deeper failure of the movement.