407 U.S. 297 (1972), argued 24 Feb. 1972, decided 19 June 1972 by vote of 8 to 0; Powell for the Court, Burger, Douglas, and White concurring, Rehnquist not participating. In the early 1970s, the nation was in a state of civil unrest. Various groups were accused of bombing buildings and plotting against the government. In the name of national security, the administration of President Richard Nixon claimed authority to use electronic surveillance to monitor American citizens allegedly involved in subversive activities without, as customarily required by the Fourth Amendment, first obtaining a warrant from a magistrate on a showing of probable cause.
The government argued that the vesting of executive power in the president in Article II of the Constitution implied authority to use electronic surveillance to secure information necessary to protect the government from destruction. A judicial warrant requirement would interfere with the executive's responsibility by increasing the risk that sensitive information would be disclosed. Moreover, judges would not be able to evaluate domestic intelligence involving issues beyond judicial expertise.
A unanimous Court rejected the administration's claim. The Court emphasized that the case involved First Amendment as well as Fourth Amendment values because political organizations antagonistic to prevailing policies are the organizations most likely to be suspected by government of raising domestic national-security dangers. In light of these First Amendment values and the vagueness of the concept of national security, the Court concluded that to permit official surveillance of domestic groups on the basis of a presidential decision without prior judicial warrant would create undue dangers of abuse.
Two days before this opinion was rendered, five men were arrested for attempting to plant electronic surveillance devices in the Democratic National Committee Headquarters in Washington, D.C., an event that initiated the Watergate affair.