The Constitution of the United States establishes a federal form of government by recognizing two forms of government: the federal (national) government and the governments of the states. This horizontal division of authority is known as federalism. The powers of the federal government are spelled out in the Constitution, but the powers of the states are not.

On the surface, the Tenth Amendment appears to establish two discrete zones of authority and one zone of rights. Beginning with the latter, the amendment protects individuals from both state and federal authority in some circumstances. This is also accomplished by the many rights explicitly protected by the Constitution and its amendments.

As to the relationship of the states to the federal government, the Constitution is not clear. Two primary theories about the relationship of federal and state authority have been asserted to define the federal–state relationship. The first is Dual Federalism. A federal system of government where both the federal and state governments are sovereign with different, and occasionally concur-rent, jurisdictions.

The second theory is hierarchical federalism. This approach positions the federal government as supreme, with the states possessing only the residual powers not possessed by the federal government. As the authority of the federal government expands or contracts, the authority of the states changes in the opposite direction.