The Dubya administration has stated, over and over, that the authorization of use of force post September 11 abrogated the requirement of a FISA Court warrant for wiretapping.
For a pack of individuals who go against broad reading of things like, oh, say, the Constitution (i.e. not finding a right to privacy, to sodomy, to abortion), to then say that the authorization to use force gives the administration limitless power is somewhat breathtaking.
But even better, Congress itself, post September 11, changed the FISA statute. Now - if, as Dubya and his Amokmitlaeufer argue, Congress had intended to get rid of the requirement of a warrant, why, then, would they later go about changing the time limits for getting a warrant?
[I would also argue that the 4th Amendment requires a warrant and that Congress and Dubya can't get rid of the requirement, period, but let's just look at Congressional intent.]