“Nullification is a constitutional theory that gives an individual state the right to declare null and void any law passed by the United States Congress which the state deems unacceptable and unconstitutional.” – Prof. David Koeller, North Park University

The Tenth Amendment Center describes nullification as follows:

“Nullification begins with a decision made in your state legislature to resist a federal law deemed to be unconstitutional. It usually involves a bill, which is passed by both houses and is signed by your governor. In some cases, it might be approved by the voters of your state directly, in a referendum. It may change your state’s statutory law or it might even amend your state constitution. It is a refusal on the part of your state government to cooperate with, or enforce any federal law it deems to be unconstitutional.”

“Nullification carries with it the force of state law. It cannot be legally repealed by Congress without amending the US Constitution. It cannot be lawfully abolished by an executive order. It cannot be overruled by the Supreme Court. It is the people of a state asserting their constitutional rights by acting as a political society in their highest sovereign capacity. It is the moderate, middle way that wisely avoids harsh remedies like secession on the one hand and slavish, unlimited submission on the other. It is the constitutional remedy for unconstitutional federal laws.”

“With the exception of a Constitutional amendment, the federal government cannot oppose (except perhaps rhetorically), a state’s decision to nullify an unconstitutional federal law without resorting to extra-legal measures. But such measures would more than likely backfire, since most Americans still affirm that might does not make right.”

Then Vice President Thomas Jefferson authored the Kentucky Resolutions of 1798 and detailed how the Constitution was supposed to be interpreted with regard to nullification.

James Madison wrote a similar resolution that was adotped by the Virginia Senate in that same year. It became known as the Virginia Resolution of 1798.

Together, these resolutions helped establish the foundation for interpretation of the Tenth Amendment to the United States Constitution.