Bush and the NSA Authorization

The argument now being made to legitimize the authorization for "wire-taps", and such, to the National Security Agency, is that the government could not quickly enough act to obtain intelligence if a warrant had to be processed through a FISA court. But what is wrong with obtaining a warrant after the fact, say within 24 hours after an intercept was made, making it then more or less legal?
However, there is something "fishy" about the NSA authroization that no one is talking about. Authorization could have been done by warrant after the fact as outlined above, but wasn't, which leaves me to believe that there is much more to the authorization issue.
For instance, who decides who the targets are and how? The only reason that the FISA court and judges would be bypassed is if the NSA were randomly throwing a broad net out, using special software that selects certain key words, in order to find their "fish". If anything suspicious was detected the suspect transmission would then be monitored at length, without going through FISA. Nice and convenient--and highly illegal--even if the President does sign off on it.
This monitoring program by NSA has to be a large scale operation, one that would effect thousands and perhaps millions of American citizens over time. A definite felonious breach of civil liberties.
Bush has broken the law and his only recourse now is to try to convince everyone he was protecting Americans and hide behind National Security--with help from his Republican apologists in the Congress. The big question is will anyone stick their political necks out for him. Probably, but I wouldn't advise it.
If anything is ground for impeachment this violation of civil rights is one of them. This act and his failed reasons for going to war with Iraq are clear indications that he is incompetant and dangerous, certainly someone who doesn't belong in the White House.
If this authorization had been revealed when it was discovered we would have another person as President--someone who at least knows the law and respects American civil rights.