The Fourteenth Amendment, ratified by the states in 1866, included among is provisions the Privileges and Immunities Clause. This clause provides that no state “shall abridge the privileges and immunities of the citizens of the United States.” Many commentators have long argued that this provision, rather than the Due Process Clause of the Fourteenth Amend-ment, should protect substantive rights of citizens. The Supreme Court, however, limited the application of the Privileges and Immunities Clause in the Slaughterhouse Cases (1872) by stating that the amendment did not create any new federal rights. The Court has rarely applied the Privileges and Immunities Clause since that time.

Although some cases during the nineteenth century suggested that the due process should protect substantive rights, the Supreme Court generally avoided this question. In Lochner v. New York (1905), however, the Court reversed its position, ruling that a state statute limiting the number of hours that employees could work violated due process because it interfered with the workers’ right to contract. After this decision, the Court engaged in a practice where it effectively substituted its own judgment for the judgment of a legislative body.

Several pieces of legislation enacted under President Franklin Roosevelt’s New Deal program were challenged on due process grounds. The Court at that time continued to strike down legislation based on the due process clause under Lochner, and the economic beliefs of the justices conflicted with the goals of Roosevelt’s legislation. In a direct clash between two of the branches of government, Roosevelt threatened to add Supreme Court justices who were more likely to uphold the statutes. Although Congress later rejected the court-packing plan, the Court nevertheless reversed its position. By 1937, the Court no longer subjected legislation to the same type of scrutiny that it did under Lochner.