The Constitutional Baseline

The Constitutional Baseline

Article III extends the federal judicial power to "cases" arising under federal law, and the question for supplemental jurisdiction is how much of a dispute counts as one case when only part of it presents a federal question. The answer came in two stages. The Supreme Court first tried a test that asked whether the claims were separate causes of action, and it later replaced that test with one built on the facts the claims share. Gibbs reframed the unit of analysis from the claim to the case: if a federal claim and a state claim are sufficiently related to form one constitutional case, Article III reaches both.¹

The limit on that reach follows from the reason for it. A dispute that includes a proper federal claim can sensibly be treated as a single case, but a state claim that merely happens to interest the same plaintiff is a different case, and Article III does not stretch to cover it. Gibbs also separated the existence of the power from the decision to use it, so that a court with constitutional power may still decline to exercise it.² Because Gibbs spoke in constitutional terms, it supplies the outer boundary, and the statutory grant that Congress later enacted is read against it.³ The sections below take the two tests in the order in which the Court produced them, beginning with the earlier one in Hurn v. Oursler and the reasons it was replaced.

Hurn's Cause-of-Action Test

The Supreme Court's first serious answer to the question of how much of a dispute a federal court may hear came in ⁵Hurn v. Oursler, decided in 1933. The plaintiffs wrote a play, The Evil Hour, and copyrighted it. They sued the owners of a rival play, The Spider, alleging that the defendants had reworked their own script by taking the plaintiffs' central idea, a spiritualist seance staged with the audience taking part, along with other material from The Evil Hour. The complaint pleaded copyright infringement, which arises under federal law, and also unfair competition, which rested on the same copying. Both sides were citizens of the same state, so the unfair-competition claim had no independent basis for jurisdiction.⁶ The trial court found no infringement and then dismissed the remaining claim for lack of jurisdiction, reasoning that once the federal claim failed there was nothing left for a federal court to decide.

The Supreme Court agreed that the federal claim was substantial enough to support jurisdiction but held that the trial court had misjudged what followed from its loss on the merits. The Court drew a line between two situations. In the first, a complaint alleges two distinct grounds in support of a single cause of action, and only one ground presents a federal question. In the second, it alleges two separate and distinct causes of action, and only one is federal. In the first situation, if the federal question is not plainly wanting in substance, the federal court may retain the case and decide it on the non-federal ground even though the federal ground fails. In the second situation, it may not decide the non-federal cause of action.⁷ The line depends on what a cause of action is. The Court, borrowing from an earlier decision, said that a cause of action consists of the unlawful violation of a right, and that the facts alleged are only the means of showing that violation.⁸ Measured that way, infringement and unfair competition based on the same copying were not two wrongs. They were, in the Court's phrase, little more than different epithets for the same group of circumstances, so the state-law label added a second ground to one cause of action rather than a second cause.⁹ The trial court should therefore have disposed of the unfair-competition claim on the merits, not dismissed it for want of jurisdiction.¹⁰

The case also contains the contrasting pole, and a single fact separates the two. While the suit was pending, the plaintiffs amended their complaint to allege that the defendants had also wronged them with respect to the uncopyrighted revision of the play. That claim rested on no federal ground and concerned a different right, the right to protection of the uncopyrighted version, so the Court treated it as a separate cause of action that belonged outside federal jurisdiction.¹¹ The reason is that a federal court has no power to hear a cause of action outside its jurisdiction just because the cause was joined in a complaint with one that is within it.¹² If joinder alone could carry a claim into federal court, a plaintiff could turn any state-law dispute between co-citizens into a federal case by attaching a federal claim. The copyrighted and uncopyrighted versions involved the same plaintiffs, the same defendants, and the same play in substance. What changed the result was whether the claim vindicated the right already before the court or a different one.

The cause-of-action test did not last, and the reason is visible in the opinion that replaced it. Gibbs observed that Hurn was decided in 1933, before the Federal Rules unified law and equity, when the meaning of "cause of action" was seriously disputed and could differ with the purpose for which the phrase was used. Hurn had defined the phrase by citing Baltimore S.S. Co. v. Phillips, a case about the scope of res judicata, which tells us the Court was drawing on the policies of judicial economy and fairness that make a plaintiff try one wrong in one proceeding.¹³ After the Rules encouraged the broadest scope of action consistent with fairness, the phrase "cause of action" remained the keystone of the Hurn test. Because the question was one of jurisdiction rather than mere convenience, courts tended to confine the test to cases like Hurn itself, where the two claims were just epithets for one set of circumstances.¹⁴ Gibbs called that approach unnecessarily grudging.¹⁵ The difficulty is structural: the test made jurisdiction depend on a label whose meaning shifted from one context to another, even though the real justification for hearing both claims is that they grow out of the same facts and would ordinarily be tried together. Gibbs kept that justification and discarded the label, which leads to the modern standard in the next section.

Gibbs's Common Nucleus Test

Each condition does separate work. Substantiality supplies the anchor that Article III requires, since the power to hear the state claim is borrowed from a federal claim that actually belongs in federal court. A federal claim that later loses on the merits still counts, because the question is whether it was frivolous enough to fail as a basis for jurisdiction, and a claim that is weak but not insubstantial passes.¹⁹ The common nucleus requirement links the two claims through the underlying events, which is what allows a court to say the whole action is one constitutional case. The third condition asks whether a sensible plaintiff would sue on both claims at once. It looks at the claims without regard to whether each is federal or state, because the point is that a court with one dispute before it is not reaching out for a second.²⁰

The test tracks the way the Federal Rules and claim preclusion already treat related claims. A plaintiff fired because of religion who sues under Title VII and adds a state wrongful-discharge claim over the same firing has pleaded two claims that rest on one event. The Rules permit that joinder, and claim preclusion would likely force it, because both claims arise from the same transaction or occurrence.²¹ A claim that is compulsory under the same-transaction standard will therefore satisfy the common nucleus standard as well. The converse is less certain, since Gibbs may reach some more loosely connected claims than the transaction test does, but the same-transaction standard is a safe guide.²²

A contrasting pair shows which fact decides the question. Suppose a plaintiff arrested by an officer sues under 42 U.S.C. § 1983 and adds a state battery claim over the same arrest. The battery claim comes from the same operative facts as the federal claim, so the court has power to hear it.²³ Now change one thing: the plaintiff also adds a claim that the same officer owes an unrelated $500 debt. The parties are the same and joinder under Rule 18 would be allowed, but the debt does not arise from the arrest. Any causal link between the debt and the arrest is too attenuated to make them one nucleus, so Article III gives the court no power over the debt claim.²⁴ Relatedness through the events also differs from relatedness through the parties. A federal antitrust claim and a state unfair-competition claim over the same conduct overlap heavily in proof. A slander claim and a personal-injury claim usually require different proof, even when the slander followed the accident minutes later.²⁵

Meeting the test gives the court power but does not oblige it to use that power. Gibbs describes the doctrine as one of discretion rather than of plaintiff's right, justified by judicial economy, convenience, and fairness to the litigants.²⁶ The two questions also run on different schedules. Power ordinarily gets resolved on the pleadings, because it depends on how the claims are framed. Discretion stays open throughout the litigation, since discovery or trial may reveal that the state claim is the real body of the case and the federal claim only an appendage, or that a joint trial is confusing the jury.²⁷ In Gibbs the federal claims ultimately failed and the plaintiff recovered only on the state claim. The Court still found no abuse of discretion in deciding that claim, because the federal issues had been substantial and had played a real part in the trial.²⁸ The specific grounds for declining are taken up with § 1367(c) later in the chapter. For now, the point is that the Gibbs power test is the Article III ceiling, and Congress later wrote it into § 1367(a) by granting jurisdiction over claims that form part of the same constitutional case.²⁹