The landmark Moore decision marked two constitutional developments: the Supreme Court’s actual utilization of the due process clause of the Fourteenth Amendment as a limitation on state criminal proceedings and the federal courts’ supervision of state proceedings by way of habeas corpus petitions.

In 1919 a violent racial clash in Phillips County, Arkansas, resulted in the deaths of scores of African Americans and five whites. More than one hundred African Americans, and no whites, were prosecuted. Swift trials took place in a lynch-mob atmosphere, with large angry crowds intimidating the juries.Jury, trial by;Moore v. Dempsey[Moore v. Dempsey]Habeas corpus[Habeas corpus]

Six defendants sentenced to death petitioned the federal district court for a habeas corpus hearing. As recently as Frank v. Mangum[case]Frank v. Mangum[Frank v. Mangum] (1915), however, the Supreme Court had refused federal relief for a defendant convicted of murder in state court under mob-influenced conditions similar to those of Phillips County. Therefore, the district court dismissed the petition.

By a 6-2 vote, the Supreme Court reversed the ruling and instructed the lower court to hold a habeas corpus hearing. Speaking for the Court, Justice Oliver Wendell HolmesHolmes, Oliver Wendell;Moore v. Dempsey[Moore v. Dempsey] observed that a trial influenced by the threat of mob violence was manifestly inconsistent with the constitutional requirements for due process of law. The state courts had the obligation to guarantee fair trials for the defendants, but if evidence indicated a failure to meet this obligation, the federal courts then had the duty to review the record and determine whether the convictions should be overturned. The two dissenters expressed concern that the ruling would result in excessive federal interference in state proceedings.

Due process, procedural

Fay v. Noia

Frank v. Mangum

Habeas corpus

Race and discrimination

Sixth Amendment