Incorporation Doctrine

The incorporation doctrine is the process through which the Supreme Court has applied the protections of the Bill of Rights — originally binding only on the federal government — to state and local governments through the Due Process Clause of the Fourteenth Amendment.

The Bill of Rights was ratified in 1791 to constrain federal power. In Barron v. Baltimore (1833), the Supreme Court confirmed that the Bill of Rights did not apply to the states. After the Civil War, the Fourteenth Amendment was ratified, providing that no state shall "deprive any person of life, liberty, or property, without due process of law." The question became whether the Fourteenth Amendment's Due Process Clause "incorporates" the Bill of Rights protections and makes them applicable against the states.

The Court initially rejected total incorporation — the idea that the entire Bill of Rights applies to the states. Instead, it adopted selective incorporation, evaluating each provision individually to determine whether it is "fundamental to the American scheme of ordered liberty" or "deeply rooted in the Nation's history and traditions." Under this approach, nearly all Bill of Rights protections have been incorporated, including the First Amendment freedoms, the Fourth Amendment's protection against unreasonable searches and seizures, the Fifth Amendment's protection against self-incrimination and double jeopardy, the Sixth Amendment's right to counsel and jury trial, and the Second Amendment right to bear arms (McDonald v. Chicago, 2010).

A few provisions remain unincorporated, including the Third Amendment's quartering of soldiers requirement, the Fifth Amendment's grand jury indictment requirement, the Seventh Amendment's civil jury trial right, and the Eighth Amendment's excessive fines clause (though this was incorporated in Timbs v. Indiana, 2019).

Incorporation is essential background knowledge for any constitutional law question involving state or local government action and Bill of Rights protections. Without incorporation, there would be no constitutional limit on states abridging speech, establishing religion, or conducting unreasonable searches.