What Is a Plurality Opinion?

Look at the first line of the opinion. A majority opinion begins: "Justice Kagan delivered the opinion of the Court." A plurality begins with a different formula: "Justice Stevens announced the judgment of the Court and delivered an opinion, in which The Chief Justice and Justice Kennedy join." That phrase — announced the judgment of the Court — is the tell. It means the author's reasoning attracted fewer than five votes even though at least five justices agreed on who wins.

Pluralities usually arise in one of three ways. Justices agree on the result but split over the governing test, as in Rapanos v. United States, 547 U.S. 715 (2006), where four justices adopted one definition of "waters of the United States" and Justice Kennedy concurred in the judgment on a different theory. Or the Court fragments across multiple rationales, as in Furman v. Georgia, 408 U.S. 238 (1972), where a short per curiam was followed by nine separate opinions. Or recusals leave fewer than nine participating justices, so five votes for a single rationale become harder to assemble.

Also watch for opinions that are majority in part and plurality in part. The Court frequently issues an opinion where Parts I and II carry five votes (marked "delivered the opinion of the Court") while Part III does not ("an opinion with respect to Part III, in which..."). The vote line at the top of the slip opinion and the syllabus's line-up paragraph tell you exactly which sections are which. Cite the majority parts as ordinary precedent; treat the plurality parts under the rules below.

The judgment binds the parties. The reasoning does not bind lower courts as a majority opinion would, because no majority of the Court adopted it. Instead, lower courts extract a holding using Marks v. United States, 430 U.S. 188, 193 (1977): "When a fragmented Court decides a case and no single rationale explaining the result enjoys the assent of five Justices, the holding of the Court may be viewed as that position taken by those Members who concurred in the judgments on the narrowest grounds."

The classic application is Regents of the University of California v. Bakke, 438 U.S. 265 (1978), where Justice Powell wrote alone on the diversity rationale and lower courts spent twenty-five years treating his opinion as controlling — until Grutter v. Bollinger, 539 U.S. 306 (2003), endorsed it for a majority. Another is Apodaca v. Oregon, 406 U.S. 404 (1972), where Justice Powell's solo concurrence supplied the operative rule on non-unanimous juries until Ramos v. Louisiana (2020) overruled it.

Sometimes a plurality-style opinion becomes controlling in practice by sheer institutional weight. The joint opinion in Planned Parenthood of Southeastern Pennsylvania v. Casey, 505 U.S. 833 (1992), was signed by three justices, but its undue-burden standard was treated as the governing test for decades. That is a function of how later courts and the Court itself treated it, not of any automatic rule.

The Supreme Court itself has acknowledged the difficulty, observing in Nichols v. United States (1994) that the Marks test is more easily stated than applied. The problem is defining "narrowest grounds." If the concurrence's rationale is a logical subset of the plurality's — reaching the same result in a smaller set of cases — the fit is clean. If the two rationales are simply different, neither is narrower; they just point in different directions.

The leading articulation of the strict view is King v. Palmer, 950 F.2d 771 (D.C. Cir. 1991) (en banc), which held that Marks applies only when one opinion is a logical subset of another, and that courts should not try to synthesize a rule from opinions that share no common analytical ground. Other courts take a broader, results-oriented approach, asking which rationale would produce the same outcome in the largest number of future cases, or counting the "median" position. A third approach treats an irreconcilable plurality as producing no binding rule at all, leaving only the judgment.

Rapanos is the standard illustration of the mess: some circuits adopted Justice Kennedy's "significant nexus" test as controlling, some allowed a party to prevail under either Kennedy's test or the plurality's, and the agencies eventually wrote regulations around the ambiguity. In Freeman v. United States, 564 U.S. 522 (2011), the Court split 4-1-4 and lower courts divided over whether Justice Sotomayor's concurrence controlled. The Court granted certiorari in Hughes v. United States, 138 S. Ct. 1765 (2018), partly to clarify Marks — and then decided the case on the merits without resolving the Marks question.

The Bluebook requires a weight-of-authority parenthetical when the cited material is not a majority opinion (Rule 10.6.1). Omitting it is a substantive error, not a formatting nit — it tells the reader the proposition lacks five votes.

Use these forms:

Start with the syllabus line-up paragraph in the U.S. Reports or the slip opinion. It states exactly who joined what, part by part. Do not rely on Westlaw or Lexis headnotes to sort this out; headnotes are drafted from the whole opinion set and often do not flag which votes support which proposition.

Next, read the concurrences in the judgment before the plurality. The concurrence is where the narrowest-grounds analysis lives, and it will usually explain precisely how it differs from the lead opinion. That difference is your Marks fault line.

Then find out what your jurisdiction has already decided. Search your circuit or state high court for the case name plus "Marks" or "controlling opinion." Many circuits have published decisions announcing which opinion in a famous plurality controls there; that answer binds you and saves the analysis. Finally, Shepardize or KeyCite with an eye to citing-reference treatment — a plurality that has been consistently followed by later majority opinions is far stronger than one that courts have splintered over.

Yes, and this is the part students most often get wrong. Marks governs how federal courts read fragmented Supreme Court decisions, but the circuits genuinely disagree about what Marks requires — the logical-subset approach, the results-based approach, and the no-binding-rule approach all have adherents, and the Supreme Court has not resolved the conflict. What drives the variation is whether a court reads "narrowest grounds" as a formal logical relationship or as a practical prediction about future outcomes.

State courts add another layer. Many state supreme courts have their own rules about what constitutes a decision of the court, sometimes requiring a majority of the full membership rather than of participating justices, and some state constitutions or statutes specify the number of votes needed to invalidate a statute. Intermediate state appellate courts also vary in whether they apply Marks to fragmented decisions of their own high court. Check your jurisdiction rather than assuming the federal approach transfers.

In writing, never describe a plurality's reasoning as "the Court held." Say "a plurality of the Court reasoned" or "the controlling opinion in X, under Marks, is Justice Y's concurrence." Then do the work: identify the votes, identify the narrowest ground, and explain why your reading controls. If the opposing rationale would produce the same result for your client, argue in the alternative and say so — that is the safest posture when Marks is contested.

On an exam, spotting that a case is a plurality is often the point. A professor who assigns Rapanos, Crawford v. Marion County Election Board, 553 U.S. 181 (2008), or Freeman is usually testing whether you notice that the vote count is fractured and can reason about which rationale governs. Flag it in one sentence, apply the narrowest-grounds analysis, and move on.