The problem with that is that we don't know the details of the NSA work that could have led to the prevention of the Boston bomb attack.
Let me give you a plausible for-instance.
Let's say that NSA intercepted communications from Chechnya to the Bomber Brothers that mentioned one of the local Boston mosques. Assume that information was sent to the President with a request for his support for a wiretap on all communications to and from that Mosque. Assume Obama turned down the NSA request.
I find that possibility to be real since Obama won't allow Mosques to be wiretapped. You assume that the failure in Boston was due to a failure by NSA. What about the FBI? What about Obama?
Be careful. This a Baby and Bathwater choice that our enemies are salivating over. And the great majority of Dems as well. Be careful what you ask for.
The danger is from within. Certainly the external threat exists, but if we have to have an all-out war with Islam & level every mosque in the world, then we can do it.
Our constitutional Republic is gasping on life support, & Obama & other traitors intend to end it. Stopping these mechanisms for spying on us will help to stop HIM & those with the same goal.