Every federal appeals court to address the question has agreed that the president may gather electronic intelligence to protect against foreign threats. This includes the special FISA appeals court, which in a 2002 sealed case upholding the constitutionality of the Patriot Act held that “the President did have inherent authority to conduct warrantless searches to obtain foreign intelligence information.” The court said it took the president’s power “for granted,” observing that “FISA could not encroach on the President’s constitutional power.”

Now, according to the inspectors general, those of us in government following the 9/11 terrorist attacks should have assumed that the usual peacetime rules for domestic wiretaps applied and interpreted FISA in a most curious way — to delete the president’s traditional authority as commander in chief to collect signals intelligence in wartime.

The 1952 Supreme Court case of Youngstown Sheet & Tube v. Sawyer is the IG’s lodestar. In Youngstown, the Court addressed President Harry Truman’s effort to seize steel mills shut down by a labor strike during the Korean War. Truman claimed that maintaining production was necessary to supply munitions and material to American troops in combat. Youngstown correctly found that the Constitution gives Congress, not the president, the exclusive power to make law concerning labor disputes. It does not, however, address the scope of the president’s power involving military strategy or tactics in war. If anything, it supports the proposition that one branch cannot intrude on the clear constitutional turf of another.