When States Defy Washington: Nullification, Sanctuary Policies, and Secession
Key takeaways
- Under the Supremacy Clause, valid federal law overrides conflicting state law, and states cannot nullify it or leave the Union, as the Supreme Court held in Texas v. White in 1869.
- States can lawfully refuse to help enforce federal law, because Washington cannot commandeer state officials, which is the legal basis for sanctuary policies.
- States can also decline federal money with strings attached, and the Court limited Congress's power to force states with funding threats in 2012.
- Most states have legalized marijuana in some form, though federal law still bans it, and only medical products moved to a lower federal schedule in 2026.
- States of both parties now sue Washington constantly: 94 multistate suits were filed against the second Trump administration by late October 2026.
- In December 2025 the Supreme Court blocked the federal deployment of the Illinois National Guard over the governor's objection.
The Constitution divides power between the national government and the states, and the line between them has been fought over since the founding. Sometimes states go beyond disagreement and openly resist federal law, through nullification, secession, or quieter forms of noncooperation.
This guide explains what states can and cannot do, the history from the nullification crisis to the Civil War and school desegregation, and today's battles over immigration, marijuana, lawsuits, and the National Guard.
Thomas Jefferson and James Madison argued in 1798 that states could judge federal laws unconstitutional, and South Carolina tried to nullify federal tariffs in 1832 until Andrew Jackson threatened force. Southern states seceded in 1860 and 1861, leading to the Civil War, and in Texas v. White in 1869 the Supreme Court held that states cannot leave the Union. When Arkansas resisted school desegregation in 1957, President Eisenhower sent troops to Little Rock, and in Cooper v. Aaron in 1958 the Court ruled that states are bound by its decisions.
Although states cannot nullify federal law, the Supreme Court has held that the federal government cannot commandeer state legislatures or officers to carry out federal programs, in cases such as New York v. United States in 1992, Printz v. United States in 1997, and Murphy v. NCAA in 2018. Congress can attach conditions to federal money, but in 2012 the Court ruled that threatening to take away all existing Medicaid funding from states that refused to expand the program was too coercive. States can also choose not to enforce federal laws themselves, leaving the job to federal agents.
Sanctuary states and cities limit how much local police and jails help immigration agents, relying on the anticommandeering rule, while other states require cooperation. In 2025 the administration listed 35 sanctuary jurisdictions and moved to cut their funding, and a judge blocked cuts to 34 of them in August. Marijuana shows another kind of defiance: most states allow medical or recreational use even though federal law bans it, and the federal government has largely chosen not to interfere. In April 2026 marijuana in FDA-approved and state-licensed medical products moved to Schedule III, while other marijuana stayed in Schedule I.
Instead of defying federal law, states increasingly sue to stop it. Republican states led by Texas sued Democratic administrations over immigration, health care, and climate rules, and Democratic states have sued Republican administrations over the same kinds of issues. By October 28, 2026, states had filed 94 multistate suits against the second Trump administration. In 2025 the Supreme Court limited universal injunctions, which had let a single judge block a policy nationwide, but states can still win broad relief in some cases.
Disputes over the National Guard sharpened in 2025 when the President federalized Guard troops for Los Angeles, Portland, and Chicago over governors' objections. On December 23, 2025, the Supreme Court refused to allow the Illinois deployment, finding the government had not shown it was unable to execute federal law with regular forces, the condition the law requires. Supporters of state resistance say it protects liberty and local self-government, as conservatives argued over gun laws and liberals over immigration. Critics say selective defiance by either side undermines the rule of law and invites conflict.
Article VI makes the Constitution and federal laws the supreme law of the land, binding on state judges and officials, who must swear to support it. When a valid federal law conflicts with a state law, the federal law wins, a principle called preemption. But the federal government has only the powers the Constitution grants it, and the Tenth Amendment reserves the rest to the states and the people, so a federal law that exceeds those powers is invalid. Courts, not states, decide which is which.
See the basics in federalism explained and states vs. federal: who does what, or the Guard fights in the National Guard explained.