More on the legality of the Bush-authorized NSA domestic surveillance program
The relevant statute, 50 U.S.C. sec. 1801(f) defines "electronic surveillance":
"(f) "Electronic surveillance" means--
(1) the acquisition by an electronic, mechanical, or other surveillance device of the contents of any wire or radio communication sent by or intended to be received by a particular, known United States person who is in the United States, if the contents are acquired by intentionally targeting that United States person, under circumstances in which a person has a reasonable expectation of privacy and a warrant would be required for law enforcement purposes;
(2) the acquisition by an electronic, mechanical, or other surveillance device of the contents of any wire communication to or from a person in the United States, without the consent of any party thereto, if such acquisition occurs in the United States, but does not include the acquisition of those communications of computer trespassers that would be permissible under section 2511(2)(i) of Title 18;
(3) the intentional acquisition by an electronic, mechanical, or other surveillance device of the contents of any radio communication, under circumstances in which a person has a reasonable expectation of privacy and a warrant would be required for law enforcement purposes, and if both the sender and all intended recipients are located within the United States; or
(4) the installation or use of an electronic, mechanical, or other surveillance device in the United States for monitoring to acquire information, other than from a wire or radio communication, under circumstances in which a person has a reasonable expectation of privacy and a warrant would be required for law enforcement purposes."
Subsection (f)(1) was analyzed by Powerline as linked to by my post here. It is pretty clear that, under this sub-definition of "electronic surveillance," the NSA program did not violate the law. However, the remaining three subdefinitions are not so easy to dismiss.
Subsection (f)(2) concerns intercepts of wire communications. "Wire communication" is a defined term in subsection (l) and basically means any hard wire (not anything "wireless"). The critical element in this subdefinition is that the interception must take place "in the United States." According to Powerline, "The NSA program, in contrast, involves international communications only, and the intercepts take place at least in part, and perhaps wholly, outside the United States." This question, it seems to me, is the critical one. I also do not know the answer.
Subsection (f)(3) concerns the interception of a radio communication (i.e., anything "wireless"). Here, the critical element is that the communication must occur wholly within the United States - i.e., "if both the sender and all intended recipients are located within the United States." Again, I don't know the answer to this one. Most likely, most of the communications the NSA intercepts fall outside this category - i.e., are wireless communications where at least one intended recipient is outside the U.S. I don't know for sure whether the NSA program exclusively monitors only those international radio communications (or whether it is even possible to so narrow the monitoring).
Finally, Subsection (f)(4) concerns monitoring anything that is not "a wire or radio communication." Who knows what that includes (maybe wireless devices that use microwaves instead of radio? infrared?). However, again the key provision is that the monitoring must be done in the U.S. If Powerline is right, most if not all of the monitoring is done outside the U.S.
Where exactly is the NSA's electronic surveillance equipment located? If it is in the U.S., then it is likely that the NSA program violates FISA. The question then becomes whether Congress has the power to limit the President's wartime monitoring of enemy communications the way FISA purports to do.
I'm not going to weigh in on that question, but the Powerline article and the debate between Robert Levy and David Rivkin cite many relevant cases. I assume that Justice Jackson's three-part analysis in his concurring opinion in the U.S. Supreme Court's decision in Youngstown Sheet & Tube v. Sawyer - the 1952 case that held President Truman's attempt to seize U.S. steel mills unconstitutional - applies. Also, note the date of the various decisions addressing the President's inherent authority (FISA was enacted in 1978; any case pre-dating 1978 might have interpreted the power under a different prong of Justice Jackson's concurrence).
There is one main point of dispute, as I see it - whether there is statutory authority for the President's actions. Mr. Rivkin says yes, citing Congress' resolution giving President Bush the ability to use "all necessary means" to wage and win the war. Mr. Levy doesn't think so, relying on FISA and the fact that Bush could have asked for specific amendments to FISA to make explicit his ability to conduct warantless surveillance as he has ordered. (If there is statutory authority, then under Justice Jackson's three tiered test, the President's inherent authority is at its most broad.)
I'll do my best to keep up on this. One thing to note, however. If - and this is a big "if" given the above - the NSA monitoring program is illegal, then it is no different than President Truman's seizure of the steel mills. Should President Truman have been impeached for taking too broad a position on his inherent powers? You have to say "yes" if you call for Bush's impeachment over the NSA program.