Damon Linker wrote a thoughtful post a while back airing the issue of the lee-way an executive should have in deploying extra-constitutional and extra-legal powers in an emergency, such as 9/11. I see every reason to respect such a power, and see it as inherent in the American presidency; at some level it also undergirds the possibility for a constitution at all. The ability of the executive to act with dispatch can be the difference between life and death. The decision, for example, to kill three pirates is not one that the legislature should be debating and pondering; it is one for a president to make in real time with limits on his knowledge.
But it is equally clear that the kind of claims that Bush and Cheney made about executive power in the context of the current conflict, especially when allied with the power to seize individuals and torture them on the basis of executive judgment alone, goes far beyond such exigencies. It goes beyond because the emergency that usually justifies this kind of exceptional action is now permanent insofar as the Jihadist threat stretches indefinitely into the future; because the remit of the power is universal in so far as it has no geographical limits, and can extend, as Jose Padilla discovered, to citizens as well as non-citizens; and it is secret, in so far as we knew nothing about the torture policies of Bush and Cheney until long after they had tortured and abused people in their captivity.