Tenth Amendment & Federalism — Reserved Powers of the States
The Tenth Amendment provides: "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." This amendment codifies the principle of federalism — the federal government is one of enumerated, limited powers, and everything not granted to it remains with the states or the people. The states retain their traditional police powers — the authority to regulate health, safety, morals, and general welfare — which is why state governments, not the federal government, primarily regulate: criminal law (most crimes are state crimes), education, family law (marriage, divorce, custody), land use and zoning, professional licensing, and most business regulation. The Tenth Amendment has experienced a significant revival in recent decades, primarily through the anti-commandeering doctrine: the principle that the federal government may not commandeer state governments — forcing state legislatures to enact federal regulatory programs (New York v. United States, 1992) or directing state executive officials to administer federal law (Printz v. United States, 1997; Murphy v. NCAA, 2018). The Tenth Amendment is both a textual reminder of structural limits on federal power and a practical tool that states use to resist federal overreach — from immigration enforcement to marijuana legalization to gun regulation. The companion Ninth Amendment reserves unenumerated rights to the people. See Commerce Clause for the primary source of federal power the Tenth Amendment constrains, Eleventh Amendment for related state sovereignty protections, and Federal Court System for where federalism disputes are resolved.
Current Law (2026)
| Parameter | Value |
|---|---|
| Constitutional provision | Tenth Amendment (1791) |
| Core principle | Powers not delegated to the federal government are reserved to the states or the people |
| Anti-commandeering | Federal government cannot compel states to legislate or administer federal law |
| State police powers | Health, safety, morals, general welfare — the states' broadest regulatory authority |
| Key cases | New York v. United States (1992), Printz v. United States (1997), Murphy v. NCAA (2018), NFIB v. Sebelius (2012) |
| Spending power limit | Congress cannot coerce states through conditions on federal funding (NFIB — Medicaid expansion) |
| Federal preemption | Valid federal law preempts conflicting state law — but Tenth Amendment limits the scope |
| Cooperative federalism | Much of federal regulation operates through federal-state partnerships (Medicaid, environmental law, unemployment insurance) |
Legal Authority
- U.S. Constitution, Amend. X — "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"
How It Works
The Tenth Amendment's most potent modern application is the anti-commandeering doctrine. In New York v. United States (1992), the Supreme Court struck down a federal law requiring states to either regulate radioactive waste according to federal standards or "take title" to the waste — Congress cannot commandeer state legislatures to enact a federal program. In Printz v. United States (1997), the Court struck down a Brady Act provision requiring state law enforcement to conduct background checks — Congress cannot direct state executive officials to administer federal regulatory programs. Murphy v. NCAA (2018) extended this further: the Court struck down a federal law prohibiting states from legalizing sports betting, establishing that Congress cannot tell states what they may not legislate any more than it can tell them what they must. Congress can't commandeer states directly, but it can use spending power to incentivize compliance — attaching conditions to federal grants. States voluntarily accept federal money and its conditions. But NFIB v. Sebelius (2012) established a limit: the ACA's Medicaid expansion threatened to strip all Medicaid funding (over 10% of most states' budgets) from states that didn't expand, which the Court held was unconstitutionally coercive. Financial pressure so overwhelming that it leaves states no realistic choice crosses from permissible inducement to impermissible compulsion.
In practice, much of American governance runs through cooperative federalism — federal-state partnerships where Congress sets minimum standards and states implement them with federal funding. Medicaid (federal funding + state administration), environmental law (EPA sets standards + states run delegated programs), unemployment insurance (federal tax + state-designed benefits), and highway safety (federal standards + state enforcement) all follow this pattern. The Tenth Amendment doesn't bar cooperative federalism — it just requires state participation to be voluntary, not compelled. This framework generates the major federal-state conflicts of the current era: immigration (states arguing federal government cannot require local police to cooperate with ICE — "sanctuary city" policies), marijuana legalization (state law permitting what federal law prohibits under the CSA), gun regulation (states enacting "Second Amendment sanctuary" laws refusing to enforce federal firearms regulations), and election administration (states resisting federal voting access mandates). The anti-commandeering doctrine is each state's legal basis for non-cooperation without violating the Supremacy Clause.
How It Affects You
If you're a state resident navigating the intersection of state and federal law: The Tenth Amendment ("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") is the constitutional foundation for the vast domain of state law that governs your daily life. Criminal law (most offenses), family law (marriage, divorce, custody, adoption), property law, contract law, professional licensing, education policy (curriculum, teacher certification), and land use are all primarily state domains. Federal power is substantial — Commerce Clause authority covers most economic activity, the Spending Clause funds federal-state cooperative programs, and the Supremacy Clause makes valid federal law supreme — but the anti-commandeering doctrine (New York v. United States, 1992; Printz v. United States, 1997) means the federal government cannot conscript state legislatures or executive officials to implement federal programs. When state and federal law conflict, federal law preempts under the Supremacy Clause — but courts interpret preemption narrowly when Congress hasn't clearly expressed an intent to displace state law.
If you're a state governor, attorney general, or state legislator: The anti-commandeering doctrine is your constitutional shield against federal mandates. The federal government can regulate private parties directly; it cannot force your state government to administer federal law, enact particular legislation, or use state resources to enforce federal programs. Printz v. United States (1997) struck down the Brady Act's requirement that local sheriffs conduct background checks — requiring state officers to execute federal laws violates the Tenth Amendment. Murphy v. NCAA (2018) extended this to "anti-authorization" statutes that prohibit states from enacting particular laws (striking down the Professional and Amateur Sports Protection Act's prohibition on state sports gambling laws). In practice: states have successfully used these principles to resist federal immigration enforcement mandates, federal marijuana enforcement conscription, and federal gun registration requirements. The flip side: states that voluntarily participate in cooperative federalism programs (Medicaid, Clean Air Act, etc.) accept conditions attached to federal funding — the limit is whether conditions become "coercive" (NFIB v. Sebelius, 2012, which found the ACA's Medicaid expansion condition was unconstitutionally coercive).
If you're a federal agency official, congressional staff member, or policy lawyer: Federal regulation must work through channels that respect state sovereignty — either by regulating private parties directly (which the Commerce Clause and other enumerated powers authorize broadly) or by incentivizing state cooperation through conditional spending (which must be related to the federal interest, clear, and not coercive). You cannot direct state officials to implement federal programs without providing federal resources and creating a genuinely voluntary partnership. The boundary between permissible conditions and impermissible coercion is still evolving post-NFIB — the Court has not clearly defined when "inducement" becomes "compulsion" beyond the extreme case of Medicaid's all-or-nothing structure. For regulatory design: "cooperative federalism" programs (Clean Water Act, OSHA, many environmental programs) where states can choose to administer federal standards themselves (with federal backup) are the established model for programs where state enforcement infrastructure is valuable and state variation is manageable.
If you're a voter, policy researcher, or advocate who cares about where decisions get made: Federalism is a structural choice about democratic accountability and policy diversity. The Tenth Amendment's reserved powers principle means that on most domestic policy questions, your state legislature is the primary decision-maker — which means state elections and state-level advocacy often matter more than federal elections for day-to-day policy. The diversity federalism creates has produced both the "laboratories of democracy" dynamic (New State Ice Co. v. Liebmann, 1932, Brandeis dissent) — states experimenting with different approaches to healthcare, minimum wage, marijuana policy, and housing — and significant inequality across states in the rights and benefits citizens receive. Recent examples of the Tenth Amendment's practical bite: Murphy v. NCAA (2018) opened the door to state sports gambling — within five years, 38 states had legalized it; state marijuana laws have proceeded without federal interference (based on enforcement discretion, not Tenth Amendment law) creating a patchwork that affects workers, businesses, and patients differently depending on where they live.
State Variations
The Tenth Amendment is fundamentally about state variation:
- States exercise reserved powers differently across every policy area — criminal law, education, taxation, professional regulation, family law
- State constitutions may provide additional structural protections for state sovereignty
- Anti-commandeering doctrine protects all states equally, but states' willingness to resist federal pressure varies
- "Laboratories of democracy" — states experiment with different policy approaches (marijuana legalization, healthcare reform, minimum wage, paid leave) that may or may not be adopted nationally
Implementing Regulations
The Tenth Amendment is a constitutional provision reserving powers to the states — no implementing regulations. It operates through judicial review of federal overreach. Key precedent includes New York v. United States (1992, anti-commandeering), Printz v. United States (1997, anti-commandeering of state officers), Murphy v. NCAA (2018, anti-commandeering of state legislatures). Executive Order 13132 (Federalism) requires agencies to consider federalism implications in rulemaking.
Pending Legislation
Tenth Amendment/federalism issues arise across all areas — see Federal Preemption and State Sovereignty.
Recent Developments
The Tenth Amendment and anti-commandeering have been central to recent disputes over immigration enforcement (federal attempts to penalize sanctuary cities), marijuana policy (state legalization vs. federal prohibition), sports betting (post-Murphy legalization wave), and COVID-19 responses (federal vaccine mandates vs. state resistance). The spending power's coercion limit from NFIB has been invoked in challenges to federal funding conditions in education, transportation, and healthcare. The balance between federal and state power remains one of the most politically and constitutionally dynamic areas of American law.
- Trump executive orders and anti-commandeering (2025): Trump's executive orders directing DHS to withhold federal funding from "sanctuary" jurisdictions — cities and counties that limit cooperation with ICE — have generated Tenth Amendment challenges. Courts have found that some funding conditions are unconstitutional because they attempt to commandeer state and local law enforcement officers into performing federal immigration functions. The anti-commandeering doctrine (Printz v. United States, 1997) bars the federal government from directing state or local officials to enforce federal law; but declining federal funding for non-cooperation (rather than affirmatively ordering cooperation) may be permissible under the spending power.
- Federalism tension over Trump agenda: The second Trump term has generated significant federalism tension with blue states. California, New York, Illinois, and other Democratic-led states have filed suits challenging Trump executive orders on immigration enforcement, environmental rollbacks (states have independent Clean Air Act authority to set stricter standards), Title IX gender identity rules, and DEI funding conditions. States have also enacted protective legislation — "shield laws" protecting individuals from prosecution in other states for activities legal in the shield state. The accumulated litigation represents one of the largest state challenges to federal authority in decades.
- Preemption and gun laws: Federal preemption of state firearm laws has been a contested federalism issue post-Bruen. Some states have enacted broad firearm regulations; others have enacted "sanctuary" laws declaring that state officials will not enforce federal gun laws. These gun sanctuary laws themselves raise anti-commandeering questions in reverse — can states direct their officials not to enforce federal law? The anti-commandeering doctrine (a protection for states) means states can't be compelled to help enforce federal law, including federal gun law; but proactively enacting sanctuary ordinances may go further than the doctrine permits.
- Spending power and Medicaid (OBBBA): The OBBBA reconciliation package's proposed Medicaid changes — mandatory work requirements, state cost-sharing, ACA expansion FMAP reduction — will be challenged under the Tenth Amendment's spending power coercion doctrine. NFIB v. Sebelius (2012) established that Congress cannot use federal funding conditions to coerce states into accepting a "gun to the head." Whether the OBBBA Medicaid conditions cross from permissible inducement to unconstitutional coercion will be litigated; the answer depends heavily on how much states would lose if they refused the conditions.