The legal memos from 2004, over a decade ago, outlining the power of the President to use wiretapping, have been obtained through a Freedom of Information Act lawsuit by the American Civil Liberties Union and Electronic Privacy Information Center.
The project was called Stellar Wind, and allowed the National Security Agency (NSA) to collect information, even when it was contained in the U.S., as long as one end of the communications was overseas and a party was believed to be connected to terrorism.
Jack Goldsmith, Assistant Attorney General at the time, wrote in a memo from May 2004,
…the President, as Commander in Chief and Chief Executive, has legal authority to authorize the NSA to conduct [this surveillance]… and thus that the operation of the STELLAR WIND program as described above is lawful.
The memo does not dismiss Congressional authority, and infers from the Foreign Intelligence Surveillance Act (FISA) and provisions under Title III of the Omnibus Crime Control and Safe Streets Act of 1968 allows for this use of power once Congress passed the Authorization for Use of Military Force (AUMF) on Sept. 18, 2001.
Although FISA maintains certain controls and balances, FISA is ambiguous enough to infer from AUMF that such authorization can be provided. Even if FISA was construed narrowly to preclude Stellar Wind, the memo argues it would be unconstitutional as an impermissible infringement on the President’s constitutional powers as Commander-in-Chief,
Indeed, defense of the Nation is an aspect of the explicit oath of office that the Constitution prescribes for the President, which states that the President shall “‘to the best of [his] Ability, preserve, protect and defend the Constitution of the United States.'” U.S. Const. art. 2. § 1. Here, we conclude that the content collection activities under STELLAR WIND are precisely a core exercise of Commander-in-Chief powers to detect and engage the enemy in protecting the Nation from attack in the midst of a war and that Congress may not by statute restrict the Commander in Chief’s decisions about such a matter involving the conduct of a campaign.
A second memo discusses this position on Stellar Wind in light of the Supreme Court’s decision in Hamdi v. Rumsfeld, which reversed a dismissal of habeas corpus, and recognized the power to detain enemy combattants while retaining the right to due process,
As demonstrated, the interception of enemy communications for intelligence purposes is a fundamental and accepted incident of war, consistent with law-of-war principles and conducted throughout our Nation’s history. As such, the electronic surveillance of al Qaeda-related communications fits comfortably within the Hamdi plurality’s analysis of measures authorized by Congress after the terrorist attacks of September 11, 2001. The Congressional Authorization allowing such surveillance must therefore trump FISA’s otherwise applicable prohibitions, just as it trumped the explicit prohibition of unauthorized detention in [statutes which state, No citizen shall be imprisoned or otherwise detained by the United States except pursuant to an Act of Congress.]