Justice Neil Gorsuch had quite the reaction when an attorney cited the amendment as an example of when Congress may pass a "duplicative" provision that doesn't do much in changing the law.

The Tenth Amendment expresses the basic principle of federalism. It is the essence of states’ rights.

For decades, Republicans advocated strongly for “states’ rights” (see 10th Amendment), keeping the federal government out of states’ business.

The Tenth Amendment emphasizes that the federal government has only those powers that the Constitution gives it.

“The Tenth Amendment is the final bill in the Bill of Rights. It was designed to limit the power of the federal government to only expressly enumerated powers.

The Tenth Amendment emphasizes that the federal government has only those powers that the Constitution gives it.

Quite the contrary, the Founders reserved that power, and others, to the states in the Tenth Amendment….The unlawful federalization of [National Guard] members has interfered with the state's ...

The 10th Amendment states, “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.” ...

The answer lies in part on the meaning of the Tenth Amendment’s reservation of non-delegated powers to the states.

Quite the contrary, the Founders reserved that power, and others, to the states in the Tenth Amendment….The unlawful federalization of [National Guard] members has interfered with the state's ...