President Nixon refused to hand over White House tapes during the Watergate investigation, claiming executive privilege. The Supreme Court rejected his claim in United States v. Nixon (1974), ruling unanimously that privilege isn't absolute. The Court recognized executive privilege exists but said criminal investigations trump secrecy claims when evidence is essential to justice.
The ruling established that executive privilege is qualified, not absolute. Presidents must show why keeping information secret serves the public interest. Courts then weigh that against the need for evidence. In Trump v. United States (2024), the Supreme Court recognized presidents have "presumptive immunity" for official acts, creating a new layer of protection beyond executive privilege for documents.