Suppose six justices vote to reverse a lower court. Four join one rationale, while two agree that reversal is required on a narrower ground. All six concur in the judgment, but no single rationale has five votes. The separate opinion may help later courts identify common ground, yet it does not automatically become a majority opinion merely because it supplied votes needed for the result. Courts must examine the actual vote alignment and the propositions accepted by the justices rather than treating the shortest opinion as controlling by default.

Concurrences serve several functions. One may narrow a majority rule, emphasize a fact the author considers decisive, reject part of the majority's reasoning, or propose a different framework for future cases. A justice can concur in full, concur only in the judgment, or join selected portions of another opinion. The heading and vote line matter because the word "concurring" alone does not reveal which propositions the justice accepted.

In a clear majority case, the concurrence is persuasive rather than controlling. In a fractured case, a narrower concurrence may become important if it represents reasoning that is logically shared by enough justices supporting the judgment. That inquiry is not simply "choose the narrowest opinion." The later court must determine whether the reasoning genuinely supplies common ground.

A concurrence can influence later doctrine, warn that a different fact would change the outcome, or invite future litigation. It still does not displace a clear majority holding because later readers prefer its reasoning. Contrast it with a dissent, which disagrees with the judgment, and with a majority opinion, whose controlling reasoning is joined by enough justices to speak for the Court.

The exam cue is agreement about result plus disagreement about reason. If the justice would send the case to the same final disposition but uses another path, the opinion is concurring. If the justice would change who wins or what judgment enters, it is dissenting at least in that part.

Video lesson: Judicial Decisions: Crash Course Government and Politics #22