Whether Memoirs v. Massachusetts supplied the governing obscenity standard before Miller even though Memoirs was decided by a fragmented Court.
Holding
Yes. Under the narrowest-grounds approach to fragmented decisions, the Memoirs plurality's test was the Court's holding and governed obscenity prosecutions before Miller.
Reasoning
A fragmented decision can have a controlling rule even when no single opinion commands five votes. The Court stated that the holding is the position taken by those who concurred in the judgment on the narrowest grounds.
Three Justices adopted the Memoirs test, while Justices Black and Douglas concurred in reversal on the broader ground that the First Amendment absolutely protects obscenity. Justice Stewart likewise concurred on a broader approach that would permit suppression only of "hard-core pornography." Thus, the Memoirs plurality supplied the narrowest rationale supporting the judgment.
The Court also emphasized the practical legal reality: every federal court of appeals to consider the question had treated Memoirs as controlling between Memoirs and Miller. Materials were protected unless the prosecution proved, among other elements, that they were utterly without redeeming social value.