I haven't seen anyone dispute that, the question is how are we deciding what sort of intercepts meet those criteria, and how do we go looking for them in the first place.
Apparently nobody outside the NSA and the White House - including elected officials who under our laws are charged with oversight of such operations - actually knows WHAT the parameters of the current interceptions policy are, and that's one of the reasons that some Republicans in Congress are concerned about this, they are starting to suspect that they have been systematically misled by the Administration as to what's actually been going on.
This Administration is been making very sweeping claims about the extent of Presidential prerogatives to operate independent of Congressional and judicial oversight and control, and ultimately such claims are sustainable only to the extent that such powers are not abused. Even one major example of clear misconduct (for example, using such powers for partisan political purposes) would likely focus intense congressional scrutiny on such programs, and IMO history strongly suggests that in the case of any administration - Democratic or Republican - as politically aggressive as this one such abuses are almost certain to occur.
And once that happens the Administration's policy of claiming sweeping powers to conduct surveillance without Congressional oversight probably ends up making us less secure.
Right now, it seems to me that the White House, and the Senate are talking past each other. The WH is saying, look you guys gave me the authority with the War Powers Act, and the Constitution gives me this authority. I also didn't bypass you, because I spoke to select members of the Senate.
The Senate (Democrats, anyways) seems to be saying "LIAR, ILLEGAL, IMPEACH HIM", yet no one has yet determined by any reasonable standard what is legal or not. From what I understand, the few times SCOTUS has decided any case even remotely like this one, they have decided on the side of the President (any President, not the current administration only).
I am also sick of the pandering on the left, screaming the illegality of an issue, that seems far from determined.
At a minimum, it seems to me (as a lay person), that even if in the end SCOTUS would determine this to be unconstitutional (which I doubt), they would also find that President Bush did use due diligence when determining his opinion, that he does have the Constitutional right to intercept communications with possible terror suspects.