What was the constitutional issue that brought US v. Nixon to the Supreme Court?

United States v. Nixon, 418 US 683 (1974)

President Nixon refused to give the Special Prosecutor (Leon Jaworski) in the Watergate Scandal tapes of recorded telephone calls between the President and various people implicated in the crime and its cover-up. Nixon attempted to invoke Executive Privilege, a constitutional protection allowing the Executive branch to withhold information from the Legislative and Judicial branches, under separation of powers.

The Supreme Court held that Nixon had to give Jaworski the tapes, because withholding them interfered with the Fifth and Sixth Amendment rights of the defendants being charged in the case. Nixon's status was considered that of an unindicted conspirator, and that the US Supreme Court had jurisdiction over the case. This decision affirmed one of the Judicial branch's checks on the Executive branch.

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