All Debts contracted and Engagements entered into, before the Adoption of this Constitution, shall be as valid against the United States under this Constitution, as under the Confederation.
This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.
The Senators and Representatives before mentioned, and the Members of the several State Legislatures, and all executive and judicial Officers, both of the United States and of the several States, shall be bound by Oath or Affirmation, to support this Constitution; but no religious Test shall ever be required as a Qualification to any Office or public Trust under the United States.
Often referred to as the supremacy clause, this article says that when state law is in conflict with federal law, federal law must prevail. Because of the great number of federal and state laws, many of which deal with the same or similar topics, there have been many lawsuits claiming that state laws conflict with federal laws and are therefore invalid. In these lawsuits, the Supreme Court generally looks at whether Congress has established a national regulatory scheme and if so, states cannot regulate in that area.
The Court also looks at whether the state law directly interferes or is in conflict with federal law. In all of these cases, the supremacy clause ensures that federal law takes priority over, or preempts, state law. The prioritizing of federal over state powers is known as the “doctrine of preemption.”
Article VI also provides that both federal and state officials— including legislators and judges— must obey the U.S. Constitution (state officials have a duty to obey their own state constitutions and laws as well). To ensure freedom of religion, this article ensures that no public official be required to practice or pledge allegiance to any particular religion.