The case involved two men charged with fraud in New Jersey who claimed Fifth Amendment protection and refused to testify during their trial.

Moody considered both the Privileges or Immunities Clause and the Due Process Clause of the Fourteenth Amendment: "The general question, therefore, is whether such a law violates the Fourteenth Amendment either by abridging the privileges or immunities of citizens of the United States or by depriving persons of their life, liberty or property without due process of law."

The case provides an early explanation of the doctrine of selective incorporation: only a portion of the Bill of Rights is applied to the states by incorporation, under the Fourteenth Amendment's Due Process Clause: "It is possible that some of the personal rights safeguarded by the first eight Amendments against National action may also be safeguarded against state action, because a denial of them would be a denial of due process of law.

Concurring with the majority, Justice Frankfurter wrote: "The Twining case shows the judicial process at its best -- comprehensive briefs and powerful arguments on both sides, followed by long deliberation, resulting in an opinion by Mr. Justice Moody which at once gained and has ever since retained recognition as one of the outstanding opinions in the history of the Court.

After enjoying unquestioned prestige for forty years, the Twining case should not now be diluted, even unwittingly, either in its judicial philosophy or in its particulars."