The Tenth Amendment’s core function is to say: if the U.S. Constitution does not give a power to the federal government, and it does not explicitly forbid that power to the states, then that power is reserved to the states or to the people.

What the Tenth Amendment Says

In full, it states that powers not delegated to the United States by the Constitution, nor prohibited to the states, are reserved to the states or the people. This language reinforces that the federal government is one of limited, enumerated powers rather than unlimited authority.

Its Main Functions

  • It embodies the principle of federalism: a division and sharing of power between the national government and the states.
  • It confirms that states retain broad “reserved powers,” such as most areas of criminal law, education policy, local health and safety regulations, and many aspects of family law, unless the Constitution says otherwise.
  • It acts as a reminder that individuals and local communities still control many aspects of life that the federal government cannot directly regulate.
  • In modern constitutional law, it underpins limits on “commandeering,” meaning the federal government cannot force states to pass certain laws or administer federal regulatory programs.

How Courts Have Interpreted It

The Supreme Court has often called the Tenth Amendment a “truism” or a statement of an existing principle: that the federal government only has the powers it was given in the Constitution. In cases like United States v. Sprague , the Court said it did not add new rights, but restated the basic structure of the Constitution.

At the same time, since the 1990s, cases like New York v. United States and Printz v. United States have used the Tenth Amendment to block federal attempts to compel state legislatures or state officers to carry out federal programs. This has turned the amendment into an important doctrinal tool for preserving state autonomy in certain areas.

Why It Still Matters Today

In current debates, people invoke the Tenth Amendment in fights over issues like marijuana legalization, “sanctuary” cities or states, gun regulations, environmental rules, and public health measures. Supporters of strong state authority argue that, in these areas, states have the right to experiment and differ from federal policy as long as they do not conflict with valid federal law.

Critics sometimes respond that other constitutional powers—like the commerce power or the Fourteenth Amendment’s enforcement power—allow robust federal action that can override state choices. The practical function of the Tenth Amendment, then, is not to give states absolute sovereignty, but to keep alive a constant boundary‑drawing conversation over how far federal power can go.

TL;DR: The function of the Tenth Amendment is to preserve a federal system where the national government has limited, listed powers, and all other powers are left to the states or the people, shaping many modern disputes over the balance between Washington and the states.

Information gathered from public forums or data available on the internet and portrayed here.