Article III, Section 2, Clause 1:

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.

The requirement that a case involve litigants who are genuinely adverse to each other imposes another limitation on the justiciability of disputes in federal court.1 The Supreme Court has interpreted Article III of the Constitution to forbid federal courts from issuing binding judgments in cases that do not present “an honest and actual antagonistic assertion of rights by one party against another.” 2 According to the Court, this adversity requirement helps ensure that the parties provide the Judiciary the factual information and legal advocacy it needs to resolve issues correctly.3 Thus, where all the parties in a case seek the same result, there is generally no “Case” or “Controversy” under Article III, and the Court lacks jurisdiction to issue a ruling.4 To the extent this limitation on federal jurisdiction derives from Article III of the Constitution, the courts may not modify it, and Congress cannot alter it without amending the Constitution.5

The adversity requirement is closely related to other constitutional justiciability doctrines, especially Article III standing6 and the bar against advisory opinions.7 As explained in greater detail below, however, the adversity requirement has diminished in importance at the same time as the Supreme Court has applied other Article III justiciability doctrines—particularly Article III standing—more stringently over time.8

Footnotes

1

See, e.g., GTE Sylvania, Inc. v. Consumers Union of U.S., Inc., 445 U.S. 375, 382 (1980) (holding that Article III limits “the business of federal courts to questions presented in an adversary context” ) (quoting Flast v. Cohen, 392 U.S. 83, 95 (1968)).

2

See U.S. Nat’l Bank of Or. v. Indep. Ins. Agents of Am., Inc., 508 U.S. 439, 446 (1993) (quoting Muskrat v. United States, 219 U.S. 346, 359 (1911)) (brackets omitted). See also Ayestas v. Davis, 138 S. Ct. 1080, 1090 (2018) ( “[C]ases and controversies in our legal system are adversarial in nature.” ).

3

See, e.g., GTE Sylvania, 445 U.S. at 382–83 (stating that “[t]he clash of adverse parties” in a lawsuit “sharpens the presentation of issues upon which the court so largely depends for illumination of difficult questions” ) (quoting O’Shea v. Littleton, 414 U.S. 488, 494 (1974)) (ellipses omitted).

4

Moore v. Charlotte-Mecklenburg Bd. of Educ., 402 U.S. 47, 48 (1971) (per curiam). See also, e.g., GTE Sylvania, 445 U.S. at 383.

5

See, e.g., Muskrat, 219 U.S. at 362 (holding that Congress “exceeded the limitations of legislative authority” by purporting to authorize federal courts to adjudicate disputes between non-adverse parties); id. at 361 (holding that Article III limits the federal judicial power to “determin[ing] actual controversies arising between adverse litigants” ).

6

See, e.g., Flast, 392 U.S. at 100 ( “[T]he standing requirement is closely related to, although more general than, the rule that federal courts will not entertain friendly suits or those which are feigned or collusive in nature.” ) (internal citations omitted); Baker v. Carr, 369 U.S. 186, 204 (1962) ( “Have the appellants alleged such a personal stake in the outcome of the controversy as to assure that concrete adverseness which sharpens the presentation of issues upon which the court so largely depends for illumination of difficult constitutional questions? This is the gist of the question of standing.” ) (emphases added).

7

See, e.g., Princeton Univ. v. Schmid, 455 U.S. 100, 102 (1982) (per curiam) ( “We do not sit to decide hypothetical issues or to give advisory opinions about issues as to which there are not adverse parties before us.” ) (emphases added); Flast, 392 U.S. at 96–97 ( “[T]he rule against advisory opinions also recognizes that such suits often ‘are not pressed before the Court with that clear concreteness provided . . . from a clash of adversary argument[.]’” ) (quoting United States v. Fruehauf, 365 U.S. 146, 157 (1961)) (emphases added); Muskrat, 219 U.S. at 362 ( “If such actions . . . are sustained, the result will be that this court, instead of keeping within the limits of judicial power, and deciding cases or controversies arising between opposing parties . . . will be required to give opinions in the nature of advice concerning legislative action[.]” ) (emphases added). See generally ArtIII.S2.C1.4.1 Overview of Advisory Opinions (analyzing the bar on advisory opinions).

8

See, e.g., United States v. Windsor, 570 U.S. 744, 755–63 (2013) (rejecting argument that defendant’s nondefense of statute challenged by plaintiff rendered the parties insufficiently adverse partly because the parties had satisfied Article III’s standing requirements).