In the early 1970s, President Richard Nixon became embroiled in the Watergate dispute. He was accused of covering up a criminal break-in at the national headquarters of the Democratic Party. Nixon denied any wrongdoing. A United States District Court judge ordered the president to produce tapes of conversations held in his office. Nixon knew that complying with the order would produce damaging evidence, probably destroying his presidency. He refused, claiming executive privilege. The case went to the Supreme Court. Nixon strongly implied that even if the Supreme Court ordered him to produce the tapes, he would refuse. What major constitutional issue did this raise?