IMHO, our LEOs already do whatever they want (i. e. warrantless spying, extrajudicial arrest, torture, etc.).
The purpose of fighting the Pats Act, etc. is to have a legal basis for challenging these actions in Court in the event one of these LEOs is caught violating the USC.
However, if the security of the US is so threatened that Constitutional rights need to be curbed to deal with these threats, then the foreign policy that incites these threats need to be modified/repealed.