What does the Doctrine of Incorporation do that the Supremacy Clause does not?

Question

According to the Federal Supremacy Clause of the U.S. constitution Federal Law supersedes even State Constitutions.

Separately, the U.S. Federal government employs a doctrine called Incorporation whereby portions of the Bill of Rights bind State governments as well as the Federal government.

The Supremacy Clause has existed since the Constitution was made the law of the land. However the doctrine of Incorporation has really only existed since 1886.

Incorporation of the Bill of Rights appears redundant in light of the Supremacy Clause. What does the doctrine of Incorporation accomplish that the longstanding Supremacy Clause does not?

Answer 1

The Supremacy clause resolves the conflict between the Federal law and the State law, but what if there's no Federal law? The Incorporation includes all government levels under the conditions that initially were thought to only to apply to the Federal government.

For example, the First Amendment says:

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

This is a restriction on the Federal legislation that didn't initially apply to the State level legislation. The incorporation lead to its application to the local governments as well.

Answer 2

Incorporation is doctrine, not law

Incorporation of the Bill of Rights is a doctrine established by the Supreme Court to meet the requirements of the Fourteenth Ammendment. The relevant portion of the 14th is:

No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

Courts came to view this as guaranteeing the protections of the Bill of Rights at all levels of government. They did this, however, piecemeal, applying specific cases and deciding individually that specific portions of the Bill of Rights were bound by due process.

The words of most of the Bill of Rights "Congess shall..." have come to be understood as not allowing any government action to remove these rights from the populace. This means executive and judicial actions, and lower government bodies, not just Congress.

The orignal Bill of Rights was a restriction on a powerful federal government by wary states. The incorporation of lower goverment entities into its requirements was a slow process, with many portions only granted well into the 20th century.

https://www.law.cornell.edu/wex/incorporation_doctrine

Answer 3

Notice that the Constitution says "Congress shall make no law respecting the establishment of religion nor prohibiting the free exercise thereof."

Now remember the context: The constitutions of the thirteen states, and the governments functioning in accordance with them, already existed before the Constitution of the United States was written. The major concern of the Constitution was how to unify the thirteen states under a federal government: What were the powers and duties of the federal government, what was the relationship between the federal and state governments, what are the relationships among the states? It was not about imposing requirements on the states (although in a few respects it did so – for example, requiring each state to be governed as a republic and not as a kingdom or oligarchy or the like).

It was Congress, not the state legislatures or the state constitutions, that was forbidden to establish religion. And forbidden to violate various other enumerated rights. Some of the states had churches established by law. (Or at least one did: Connecticut established one of the mainstream Protestant denominations.) There was no intention to interfere with that. If the Constitution had said "Establishment of religion shall not exist anywhere within the United States.", that would be different.

So it was only when the 14th Amendment dealt with post-Civil-War issues that "incorporation" went into effect.