Shortly after news of the NSA spying on domestic electronic communications broke there was a chorus of folks singing out a host of variations on the same theme, all of which could be summed up by the following - "I'd give up some of our liberties in exchange for safety".
While reaction to both the spying and its apologists has been mixed, I believe that there is an essential point being missed - Making the trade of "safety for liberty" isn't the President's, nor the public claiming to want it, decision to make! We are a nation founded on the rule of law, and in this case the law is quite plain ("A person is guilty of an offense if he intentionally...(1) engages in electronic surveillance under color of law except as authorized by statute"...) There is no addendum to the law, or for that matter the Constitution that says "unless we're scared, and in that case all bets are off".
Look, it's quite simple really, if we as a nation decide to give up our freedoms, ala the Patriot Act, then it's up to Congress to create the law, the President to enact it, and the Courts to ensure that it's consistent with the Constitution. Until that happens for anyone (Presidents included) to do otherwise is breaking the law. Period.