What was the Court’s decision in United States v. Nixon (1974) and how did the decision uphold the idea that even the President of the United States is not above the nation’s laws?

The Supreme Court decided that the President was required to turn over tape recordings and other materials that had been subpoenaed by special prosecutor Leon Jaworski.

In trying to withhold some materials related to the Watergate investigation, Nixon's lawyer had argued that the President of the United States "is not subject to the processes of any court in the land except the court of impeachment." The Supreme Court disagreed, in unanimous fashion. They held that the President could not use executive privilege as an excuse for hiding wrongdoing or avoiding prosecution. In an interview some years after his resignation, Nixon still held to his view, claiming that when the President does something, "that means that it is not illegal." He felt that being in the position of President put him above the law. But the Supreme Court had firmly disagreed. They rejected the idea of "absolute, unqualified Presidential privilege of immunity from judicial process under all circumstances." Executive privilege can only protect matters of military or diplomatic confidentiality