Powerlineblog.com is doing a great job of putting forward the legal arguments in this regard. They have a great one today from a former federal prosecutor about a Supreme Court ruling exactly on point, Dickerson v. United States. the post is titled A Word From Bill Otis."
Thanks. I've been collecting this stuff.
Thanks for the link. FWIW, I find the argument raised by the former prosecutor to be bizzare, and weak. Under his analysis, Congress can make NO statute that limits a president's warime powers, and that proposition is demonstrably false: see Korematsu, Milligan, etc.
The path to FISA has two branches, political and judicial.
The government had long maintained that it had extensive discretion to conduct wiretapping or physical searches in order to protect national security. In Katz v. United States, 389 U.S. 347 (1967), the Supreme Court acknowledged that the President had claimed special authority for warrantless surveillance in national security investigations, and explicitly declined to extend its holding to cases "involving the national security." Id. at 358 n. 23. Similarly, Congress in Title III stated that "nothing in Title III shall . . . be deemed to limit the constitutional power of the President to take such measures as he deems necessary to protect the United States against the overthrow of the Government by force or other unlawful means, or against any other clear and present danger to the structure or existence of the Government."
On the political front, such executive branch activities, charitably described as "some degree of domestic overreaching of intelligence into domestic areas," had long been tolerated. Staff of House Permanent Select Comm. on Intelligence, 104th Cong., Staff Study, IC21: Intelligence Community in the 21st Century at 272 (comm. print 1996).
But in the 1970s the political winds changed. The 1975-76 Church Committee hearings documented extraordinary federal government abuse of surveillance powers. Examples included the the NSA's Operation Shamrock and Operation Minaret, CIA's Operation CHAOS, the FBI's COINTELPRO domestic harassment of dissenters and anti-war protesters that included illegal wiretapping, and the illegal burglaries of the Nixon White House "plumbers."
The Church Committee Report found that covert action had been excessive, had circumvented the democratic process, and had violated the Constitution. It concluded that Congress needed to prescribe rules for intelligence activities.
http://www.eff.org/Censorship/Terrorism_militias/fisa_faq.html