You don't have to take my word for it. I'm certainly not a lawyer and I doubt if you are, either. The former Clinton administration Assistant Attorney General is, and he's very familiar with these laws and court rulings. Just because you don't like what he wrote, it doesn't mean that he's wrong and you're right.

In 1980, the 4th Circuit Court ruled in TRUONG DINH HUNG v. U. S , 439 U.S. 1326 (1978) 439 U.S. 1326 that:

The Truong court, as did all the other courts to have decided the issue, held that the President did have inherent authority to conduct warrantless searches to obtain foreign intelligence information. It was incumbent upon the court, therefore, to determine the boundaries of that constitutional authority in the case before it. We take for granted that the President does have that authority and, assuming that is so, FISA could not encroach on the President’s constitutional power. The question before us is the reverse, does FISA amplify the President’s power by providing a mechanism that at least approaches a classic warrant and which therefore supports the government’s contention that FISA searches are constitutionally reasonable.

BTW: The President mentioned in this case was Jimmy Carter.

Whether we like it or not, the government does conduct many types of surveillance, even on American citizens. Remember the Walker spy family? They were American citizens and also agents of a foreign power (the former Soviet Union). The damage they did to national security cost billions to repair. Was going after them a bad thing?

How about the FBI and other law enforcement agencies when they infiltrate and investigate organizations like the KKK and the militias (as they did back in the 1990s and before). Was that a bad thing? Was that any different than investigating domestic terrorism groups like EPF or groups whose stated purpose is to undermine the military? The police also have a history of infiltrating protests to see that things don't get out of hand.

One of the key findings of the 9/11 Commission was the failure to share information between law enforcement agencies and the Intelligence Community. This failure was largely the result of a legal barrier erected over the years (and reenforced by 9/11 Commission member Jamie Gorelick). The Patriot Act removed most of those legal barriers, allowing for a better opportunity to "connect the dots" (as in "failure to connect the dots" prior to 9/11). Can such power be abused? Yes. Has it been? So far, I have not seen any evidence of that, but it does bear watching.