The Case or Controversy Clause of Article III of the United States Constitution (found in Art. III, Section 2, Clause 1) has been deemed to impose a requirement that United States federal courts are not permitted to hear cases that do not pose an actual controversy — that is, an actual dispute between adverse parties which is capable of being resolved by the court. The Court and legal scholars commonly refer to the issue of whether a "case or controversy" exists as the concept of standing.
The entire clause in the Constitution reads as follows:
| “ | The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and Treaties made, or which shall be made, under their Authority;--to all Cases affecting Ambassadors, other public ministers and Consuls;--to all Cases of admiralty and maritime Jurisdiction;--to Controversies to which the United States shall be a Party;--to Controversies between two or more States;--between a State and Citizens of another State;--between Citizens of different States;--between Citizens of the same State claiming Lands under Grants of different States, and between a State, or the Citizens thereof, and foreign States, Citizens or Subjects. | ” |
This clause, in addition to setting out the scope of the jurisdiction of the federal judiciary, prohibits courts from issuing advisory opinions, or from hearing cases that are either unripe, meaning that the controversy has not arisen yet, or moot, meaning that the controversy has already been resolved.
The earliest expression by the United States Supreme Court of adherence to this requirement came during the presidency of George Washington. Washington sent a letter to the Court asking for their approval should he choose to seek advice from them from time to time on matters that might not come before the Court in a timely manner. Chief Justice John Jay wrote in his response that, although the members of the Court had great confidence in the ability of the president to receive appropriate advice from his executive officers, the Court itself was constitutionally bound not to go beyond its role as an arbiter of judicial questions.
The most famous case setting forth the parameters of this requirement is Muskrat v. United States, 219 U.S. 346 (1911), in which the Court held that when Congress paid the legal bills for both the plaintiffs and the defendant (in this case the U.S. Treasury department, by designation), then there was no real controversy between the parties, and a judgment of the Court would be the equivalent of an advisory opinion.
The controversial case of Roe v. Wade was a notable exception to the actual controversy requirement. Justice Harry Blackmun wrote that due to the natural limitation of the human gestation period, issues concerning pregnancy will always come to term before the appellate process is complete. Roe v. Wade 410 U.S. 113 (1973). In essence, the rigid application of the actual controversy requirement would effectively deny review. Therefore, the Supreme Court held that a ban on abortion was unconstitutional despite the issue being moot.