Greene v. McElroy
United States Supreme Court
360 U.S. 474 (1959)
Though the National Security Act creating the Department of Defense never explicitly authorized a security-clearance program, the DoD implemented one anyway; aeronautical engineer Greene (plaintiff), whose private-employer job required clearance, was discharged after the DoD revoked his clearance following a hearing that denied him the rights to confront and cross-examine witnesses against him. The government argued congressional authorization could be inferred from various related statutes recognizing the importance of military secrecy and from Congress's continued funding of the DoD's clearance program; the lower court ruled for the government.
Whether congressional or executive acquiescence or implied ratification is enough to show an effective delegation of authority to take actions that are potentially contradictory to long-accepted constitutional requirements.