I'm just going to quote Dahlia Lithwick here and recommend that everyone go read it. I'm not a big fan of Slate, but she does yeoman work.
This is not simply the theory of a unitary executive at work; this isn't the notion that the president makes the law, and acts of Congress are legal elevator music. This vision of executive power is that the law not only emanates from the president but also ebbs and flows with his hunches, hopes, and speculations, on a moment-to-moment basis. What we are hearing now from senior Bush administration officials is that if the president thinks someone looks kinda like a terrorist and the information sought from him seems kinda worth getting, it will be legal to torture him. And it's legal no matter who justified it, regardless of the supporting legal doctrine, because, well, the president just had a feeling that the information would prove valuable.
That's not an imperial presidency. That's the kind of presidency Yahweh might establish. I'm sure there's some law professor out there who can make the legal argument that executive power in wartime encompasses even the reckless guesses and impressionistic whims of a single man, as they arise. At which point, that too will become an "open question" on which "reasonable people will differ." And the dance will begin again.
http://www.slate.com/id/2182348/