The Forgotten Footnote Four:
Those who believe the President has inherent Article II authority to conduct foreign intelligence monitoring in violation of FISA often rely for authority on United States v. Truong, 629 F.2d 908 (4th Cir. 1980). For example, the DOJ's defense of the program cites Truong (among other cases) for the view that "the President has inherent constitutional authority, consistent with the Fourth Amendment, to conduct searches for foreign intelligence purposes without securing a judicial warrant."

  As far as I know, however, believers in the strong Article II argument have not mentioned the very interesting footnote four of the Truong case. This footnote is particularly relevant, as it addresses the effect of the then-recently enacted FISA statute on the Court's analysis. FISA wasn't directly implicated in the Truong case because the monitoring had occurred before the statute was passed. But in the footnote, the Fourth Circuit explained why the Court didn't impose a Fourth Amendment requirement on limited foreign intelligence monitoring even after Congress had passed FISA.

  Here is the explanation for the Court's deference:
    While [FISA] suggests that it is possible for the executive branch to conduct at least some types of foreign intelligence surveillance while being subject to a warrant requirement, the complexity of the statute also suggests that the imposition of a warrant requirement, beyond the constitutional minimum described in this opinion, should be left to the intricate balancing performed in the course of the legislative process by Congress and the President. The elaborate structure of the statute demonstrates that the political branches need great flexibility to reach the compromises and formulate the standards which will govern foreign intelligence surveillance. Thus, the Act teaches that it would be unwise for the judiciary, inexpert in foreign intelligence, to attempt to enunciate an equally elaborate structure for core foreign intelligence surveillance under the guise of a constitutional decision. Such an attempt would be particularly ill-advised because it would not be easily subject to adjustment as the political branches gain experience in working with a warrant requirement in the foreign intelligence area.
(emphasis added)

  So here is my question for believers in the strong Article II argument: If Congress has no legitimate role in regulating foreign intelligence monitoring, why is the United States Court of Appeals for the Fourth Circuit stepping aside so that "the political branches" (plural) can "reach the compromises" as part of "the legislative process"? Doesn't this necessarily mean that the Fourth Circuit thought "the compromises" of FISA were binding on the Executive Branch?

  I look forward to reading careful, focused, and thoughtful responses to this question.