Which case limited presidential power by ruling that executive privilege is not absolute and must yield to the law?

• A. Buckley v. Valeo
• B. Katz v. United States
• C. Brown v. Board of Education
• D. United States v. Nixon

Answer: (D)

Executive privilege has limits: it can protect confidential presidential communications, but it is not absolute and must yield when needed to enforce the law. In United States v. Nixon, the Supreme Court recognized the privilege but rejected an absolute claim of it in a criminal case. When faced with subpoenas for White House tapes and documents in the Watergate investigation, the President argued that disclosure would violate executive privilege. The Court held that the needs of a criminal investigation and the administration of justice outweighed a generalized claim of privilege, so the tapes and related materials had to be produced. This decision established that presidential privilege is not unlimited and remains subject to judicial review and the rule of law.

The other choices address different issues: Buckley v. Valeo concerns campaign finance and First Amendment considerations, Katz v. United States deals with privacy and searches, and Brown v. Board of Education concerns racial segregation and equal protection. None of these revolve around limiting presidential power via executive privilege.