Looks like W reserves the right to occupy the White House as long as he feels it to be necessary.
Bush To Be Dictator In A Catastrophic Emergency:
The Bush administration has released a directive called the National Security and Homeland Security Presidential Directive. […] In this directive, Bush declares that in the event of a “Catastrophic Emergency” the President will be entrusted with leading the activities to ensure constitutional government. The language in this directive would in effect make the President a dictator in the case of such an emergency.
He’s willing to burn the Constitution in order to save it.
[h/t]