States' rights

In American political discourse, states' rights refers to political powers reserved for the state governments rather than the federal government according to the United States Constitution, reflecting especially the enumerated powers of Congress and the Tenth Amendment. The enumerated powers that are listed in the Constitution include exclusive federal powers, as well as concurrent powers that are shared with the states, and all of those powers are contrasted with the reserved powers—also called states' rights—that only the states possess.

The balance of federal powers and those powers held by the states as defined in the Supremacy Clause of the U.S. Constitution was first addressed in the case of McCulloch v. Maryland (1819). The Court's decision by Chief Justice John Marshall asserted that the laws adopted by the federal government, when exercising its constitutional powers, are generally paramount over any conflicting laws adopted by state governments. After McCulloch, the primary legal issues in this area concerned the scope of Congress' constitutional powers, and whether the states possess certain powers to the exclusion of the federal government, even if the Constitution does not explicitly limit them to the states.

The Supremacy Clause of the U.S. Constitution states:

In The Federalist Papers, ratification proponent Alexander Hamilton explained the limitations this clause placed on the proposed federal government, describing that acts of the federal government were binding on the states and the people therein only if the act was in pursuance of constitutionally granted powers, and juxtaposing acts which exceeded those bounds as "void and of no force":

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