As usual, Greenwald gets to the critical point:
The DOJ is not the law. They are not above the law and they do not make the law. They are merely charged with enforcing it. The fact that they assert that blatantly illegal conduct is legal does not make it so. DOJ officials, like anyone else, can violate the law and have done so not infrequently. High DOJ officials -- including Attorneys General -- have been convicted of crimes in the past and have gone to prison.
Embracing this twisted notion that the DOJ has the authority to immunize any conduct by high government officials or private actors from the reach of the law is a recipe for inevitable lawlessness. It enables the President to break the law, or authorize lawbreaking, simply by having his political appointees at DOJ -- including ideologues like John Yoo -- declare that he can do it. As these incidents ought to demonstrate rather vividly, the mere fact that Bush officials at the DOJ declare something to be legal cannot provide license to break the law with impunity.
This is why this is a bigger issue than just this particular case. If this notion is not rebuffed then the Republic cannot survive. There will always be officials who will argue that this emergency is unprecedented and our liberty is compromising our safety. We can't accept that argument and remain a Constitutional Republic.