If I may revise and extend my remarks on Benjamin Wittes slightly, I’d like to clarify that my view isn’t quite that “we have enough experience with this administration that it’s not wholly mysterious how unclear provisions might be interpreted.” This could be construed as a manifestation of the dread Bush Derangement Syndrome, but realistically the point is completely independent of the specific characteristics of this administration.
Laws like the semi-repealed FISA came into place because the Watergate investigation eventually uncovered a whole series of Nixon administration abuses of power that were, in important ways, continuous with abuses under the Johnson administration and in some ways going all the way back to FDR. Nixon was worse than the others, but what he did wasn’t totally out of left field. If we were merely talking about setting up the potential for Bush to do abusive things in some ways that wouldn’t be so bad since, after all, he won’t be president for much longer. But the next administration, of either party, isn’t going to be immune from the laws of human nature — given the opportunity, they’ll take about as much power as they think they can get away with taking.