I don't think so.
I know there is always that option available to him if things got messy here, but the higher powers would lose a shitload of money. Our already teetering economy and RE market would collapse. And Bush/cheney would stop earning, personally.
I remember reading these same things 15 years ago. I think the threat is always there, but the economy would just collapse and tax dollars would end since people would stop going to work.
Now, if a rummy or silverstein deathbed confession video were to hit youtube and the world suddenly found out about 911 and people got violent, then yes, it would happen. But I think opportunisitic senators who knew all along would get in front of it and lead the charge for the show trials, appeasing the masses as they watched the fall guys on CourtTV.