Federalism in the United States

Federalism is the division of governmental power between a national (federal) government and subnational (state) governments. The United States pioneered modern federalism — creating a system where both levels of government have direct authority over citizens, rather than states being mere subordinates of the federal government.

Learning Objectives

By the end of this topic, you should be able to:

• Distinguish enumerated, reserved, and concurrent powers and identify which level of government exercises each
• Explain the Supremacy Clause (Article VI) and how it resolves conflicts between federal and state law
• Trace how Commerce Clause interpretation expanded federal power from 1824 to the present, and where the Court has drawn limits
• Identify the three types of preemption and apply them to a real regulatory conflict
• Explain the anti-commandeering doctrine and why Congress cannot force states to enforce federal law
• Compare dual federalism, cooperative federalism, and New Federalism as models of federal-state relations

Quick Answer

Federalism divides power between the national government and the states, with both deriving authority directly from the Constitution rather than one from the other. The Constitution gives the federal government specific enumerated powers (Article I, Section 8), while the 10th Amendment reserves everything else to the states. When federal and state law genuinely conflict, the Supremacy Clause (Article VI) makes federal law win — but only if that federal law is itself constitutional. The Commerce Clause has been the main engine of federal power growth since the 1930s, though the Supreme Court has periodically reasserted limits (Lopez, Printz). Federalism is not static: it has shifted from strict separation ("dual federalism") to heavy cooperation via grants-in-aid ("cooperative federalism") to a partial revival of state autonomy ("New Federalism") since the 1990s.

The Constitutional Foundation

Enumerated, Reserved, and Concurrent Powers

Enumerated (express) powers are the powers the Constitution specifically lists for the federal government — mainly in Article I, Section 8: coining money, declaring war, raising armies, regulating interstate and foreign commerce, establishing post offices, and more. Congress can only act where the Constitution grants it authority (plus whatever is "necessary and proper" to carry those powers out).

Reserved powers belong to the states. 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."

Because the states never had to be granted power in the first place — they already had it as pre-existing sovereign governments — the 10th Amendment isn't a grant so much as a reminder: whatever the Constitution doesn't hand to Washington stays with the states.

Concurrent powers are held by both levels of government simultaneously. The clearest example is taxation: nothing stops the federal government and a state government from both levying an income tax on the same paycheck. Other concurrent powers include making and enforcing laws (federal crimes and state crimes often overlap), borrowing money, and — within limits — regulating the environment.

This structure produces dual sovereignty: unlike a confederation, where the central government exists only through the consent of the states, the US federal government and the state governments both act directly on citizens and both derive their authority from the same source — the Constitution.

Real-world example: A person selling marijuana in California may simultaneously satisfy state law (legal recreational sale) and violate federal law (Controlled Substances Act, a valid exercise of the Commerce Clause power). Both governments have independent, overlapping jurisdiction over the same conduct — that's dual sovereignty in action, and it's also why the marijuana question below is genuinely unresolved rather than just badly enforced.

Common misunderstanding: Students often assume the 10th Amendment gives states a specific list of powers, similar to Article I, Section 8. It doesn't — it's a residual category. Anything not given to the federal government (and not forbidden to the states) belongs to the states, whatever that turns out to be.

The Supremacy Clause (Article VI)

"This Constitution, and the Laws of the United States which shall be made in Pursuance thereof... shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding."

When federal and state law genuinely conflict, federal law wins — this is the foundational rule of American federalism. Note the qualifier "made in Pursuance thereof": a federal law only trumps state law if it is itself a constitutional exercise of federal power. An unconstitutional federal statute doesn't automatically beat state law just because it's federal.

Why it matters: Without the Supremacy Clause, the country could have 50 different sets of rules on matters requiring national uniformity — currency, interstate transportation safety standards, immigration status. The clause is what lets Congress make binding national policy at all.

Common misunderstanding: Students often think the Supremacy Clause means the federal government always wins on any issue. In reality, states retain full authority wherever the Constitution is silent or the federal government hasn't validly acted — the Supremacy Clause resolves conflicts, it doesn't extend federal power into new areas by itself.

The Commerce Clause — The Big Expander

Article I, Section 8 grants Congress the power to "regulate Commerce with foreign Nations, and among the several States." This seemingly narrow clause has become the constitutional basis for enormous federal regulatory power — everything from labor law to civil rights to environmental protection rests on it.

Case	Year	Holding
Gibbons v. Ogden	1824	"Commerce" includes navigation; Congress has broad power over interstate commerce
Wickard v. Filburn	1942	Even purely local economic activity (wheat grown for personal use) can be regulated if it in the aggregate affects interstate commerce
Heart of Atlanta Motel v. US	1964	Civil Rights Act's public accommodations provisions justified under the Commerce Clause
United States v. Lopez	1995	First time since 1937 the Court limited the Commerce Clause — the Gun-Free School Zones Act was not a regulation of economic activity
NFIB v. Sebelius	2012	ACA's individual mandate could not be justified under the Commerce Clause (upheld instead as a tax)

Real-world example: Wickard v. Filburn is the extreme case worth remembering — a farmer growing wheat for his own family's consumption, never selling it across state lines, was still subject to federal quotas, because if every farmer did the same thing, national wheat prices would be affected "in the aggregate." That single case explains why the modern federal government can regulate things that look purely local.

Common misunderstanding: Students assume Lopez (1995) reversed decades of Commerce Clause expansion. It didn't — it drew a boundary (Congress can't regulate non-economic activity just by claiming an aggregate effect) without touching the vast body of regulation built on Wickard and Heart of Atlanta.

Powers of the Federal Government

Exclusive federal powers — states cannot exercise these:

• Coin money and regulate its value
• Establish post offices
• Declare war
• Raise an army and navy
• Negotiate treaties with foreign nations
• Regulate immigration and naturalization
• Govern U.S. territories

Federal powers over interstate commerce (very broad after 1937):

• Environmental regulation (EPA)
• Labor law (NLRA, FLSA)
• Civil rights in employment and public accommodations
• Securities regulation (SEC)
• Food and drug safety (FDA)

Powers of State Governments

The 10th Amendment reserves substantial power to states — what is sometimes called the "police powers": broad authority to legislate for the public health, safety, welfare, and morals of state residents.

Areas primarily governed by states:

• Criminal law (most crimes are state offenses)
• Education (K-12 and public higher education)
• Marriage and divorce
• Professional licensing (doctors, lawyers, contractors)
• Property law
• Corporations and business law (Delaware dominates)
• Elections administration (voter registration, polling, etc.)
• Zoning and land use
• Traffic laws

Preemption

When Congress validly acts in an area, it can preempt (displace) state law. There are three types:

1. Express preemption: The federal statute explicitly states it preempts state law (e.g., ERISA preempts state employee benefit laws)
2. Implied preemption — field preemption: The federal regulatory scheme is so pervasive it implies Congress intended to "occupy the field" (e.g., immigration law)
3. Implied preemption — conflict preemption: State law makes it impossible to comply with both federal and state law, or state law "stands as an obstacle" to federal purposes

Real-world example: Arizona's SB 1070 (2010) immigration enforcement law was mostly preempted by federal immigration law (Arizona v. United States, 2012) — because immigration is primarily a federal domain and Congress had already built a comprehensive federal scheme.

Why it matters: Preemption is the practical battlefield of federalism disputes today — from state vehicle emissions rules to state data-privacy laws to state marijuana laws, most modern federalism litigation is really a preemption fight in disguise.

The Evolution of Federalism

Dual Federalism ("Layer Cake") — 1789 to 1937

Federal and state governments operate in separate, distinct spheres with minimal overlap. The Commerce Clause is interpreted narrowly. States are the primary regulators of daily life. This model collapsed during the New Deal, when the scale of the Great Depression made a purely state-by-state response impossible.

Cooperative Federalism ("Marble Cake") — 1937 to 1990s

After FDR's New Deal programs, federal and state governments cooperate extensively through grants-in-aid:

• Categorical grants: Federal money given for specific purposes with conditions (e.g., highway funds tied to a 55 mph speed limit)
• Block grants: More flexible federal money for broad purposes (e.g., CDBG for community development)

The federal government can attach conditions to federal funds as a way to regulate state behavior without directly commandeering them — South Dakota v. Dole (1987): Congress can withhold highway funding if states don't set the drinking age at 21; the Court upheld this condition as not unduly coercive. NFIB v. Sebelius (2012): the ACA's Medicaid expansion went too far — threatening to withdraw all existing Medicaid funding for non-compliance was unconstitutionally coercive, resembling "a gun to the head" rather than a mere inducement.

New Federalism — 1990s to Present

The Rehnquist and Roberts Courts have revived some limits on federal power:

• United States v. Lopez (1995): Commerce Clause limits — Congress cannot regulate non-economic activity just by asserting an aggregate effect on commerce
• Printz v. United States (1997): Anti-Commandeering Doctrine — Congress cannot compel state officers to implement federal law (struck down the Brady Act's requirement that state sheriffs conduct background checks)
• New York v. United States (1992): the federal government cannot "commandeer" state legislatures into passing particular laws

Why it matters: The anti-commandeering doctrine is why the federal government cannot simply order state police to enforce federal immigration law or state legislatures to pass a particular gun-control statute — it can only regulate directly, or offer funding incentives, never issue direct orders to state governments as governments.

Current Federalism Controversies

Marijuana: Federal law (Controlled Substances Act) classifies marijuana as Schedule I; 24+ states have legalized recreational marijuana. Federal law technically preempts, but the federal government has largely declined to enforce — creating a unique federalism grey zone.

Immigration sanctuary cities/states: Some cities and states decline to cooperate with federal immigration enforcement. Courts have held that cities/states cannot be compelled to enforce federal immigration law (anti-commandeering), but may be denied certain federal grants.

Abortion post-Dobbs: Since Dobbs v. Jackson (2022) returned abortion regulation to the states, states have diverged dramatically — from near-total bans to protected rights.

Environmental standards: California has long received waivers to set stricter vehicle emissions standards than EPA minimums; other states can adopt the federal standard or California's standard.

Key Terms

Term	Definition	Related Concept
Federalism	Division of governmental power between a national government and subnational (state) governments, both deriving authority directly from the Constitution	Dual sovereignty
Enumerated Powers	Powers specifically listed for the federal government, mainly in Article I, Section 8	Reserved powers
Reserved Powers	Powers not delegated to the federal government and not prohibited to the states, kept by the states or the people under the 10th Amendment	10th Amendment
Concurrent Powers	Powers held simultaneously by both federal and state governments, such as taxation	Enumerated powers
Supremacy Clause	Article VI provision making valid federal law supreme over conflicting state law	Preemption
Commerce Clause	Article I, Section 8 power letting Congress regulate interstate and foreign commerce; the main basis of modern federal regulatory power	Wickard v. Filburn
Preemption	Displacement of state law by valid federal law; can be express, field, or conflict preemption	Supremacy Clause
Police Powers	States' broad reserved authority to legislate for public health, safety, welfare, and morals	Reserved powers
Anti-Commandeering Doctrine	Rule that Congress cannot compel state legislatures or officers to enforce federal law or policy	Printz v. United States
Categorical Grant	Federal funding given for a specific purpose with attached conditions	Cooperative federalism
Block Grant	Federal funding given for a broad purpose with more state discretion than a categorical grant	Cooperative federalism
Dual Federalism	"Layer cake" model (1789–1937) in which federal and state governments operate in largely separate spheres	Cooperative federalism

Common Mistakes

Misconception: The 10th Amendment gives states a specific, enumerated list of powers, just like Article I, Section 8 does for Congress. Why it's wrong: The 10th Amendment contains no list at all — it is a residual clause. It simply confirms that whatever powers the Constitution doesn't give to the federal government (and doesn't forbid to the states) remain with the states or the people. Correct understanding: To know what a state can do, you generally start by asking whether the federal government has been given that power exclusively or has validly preempted the field; if not, the state's broad "police powers" fill the gap. There is no fixed checklist of "state powers" the way there is for federal powers.

Misconception: The Supremacy Clause means federal law automatically overrides any state law it conflicts with. Why it's wrong: The Supremacy Clause only applies to federal laws "made in Pursuance" of the Constitution — meaning the federal law must itself be a valid, constitutional exercise of an enumerated (or otherwise granted) power. An unconstitutional federal statute has no supremacy over state law. Correct understanding: Before concluding federal law wins a conflict, first check whether Congress actually had constitutional authority to pass that law in the first place (often analyzed under the Commerce Clause or another enumerated power).

Misconception: The federal government can order state governments and their employees to carry out federal programs. Why it's wrong: The Supreme Court's anti-commandeering doctrine (New York v. United States, 1992; Printz v. United States, 1997) holds that Congress cannot directly compel state legislatures to pass laws or state officers to enforce federal regulatory programs — that would destroy the accountability of state governments to their own voters. Correct understanding: The federal government can regulate directly (using its own agencies and officers), or it can offer states money with conditions attached (cooperative federalism) to incentivize cooperation — but it cannot issue direct orders to state governments as governments.

Comparison and Connections

Model	Period	Federal-State Relationship	Key Example
Dual Federalism	1789–1937	Separate, largely non-overlapping spheres of authority ("layer cake")	Narrow reading of Commerce Clause pre-New Deal
Cooperative Federalism	1937–1990s	Extensive cooperation via grants-in-aid with conditions ("marble cake")	Highway funds tied to the 55 mph speed limit and drinking age
New Federalism	1990s–present	Partial revival of state autonomy and limits on federal commandeering	Lopez (1995), Printz (1997)

Power Type	Who Holds It	Example
Enumerated	Federal government only	Coining money, declaring war
Reserved	State governments only	Education, marriage law, most criminal law
Concurrent	Both federal and state	Taxation, criminal law enforcement
Prohibited	Neither level (or one level specifically)	States cannot coin money; neither level can grant titles of nobility

Practice Questions

Recall

1. What does the 10th Amendment say, and what kind of power does it describe? Answer guidance: It reserves all powers not delegated to the federal government (and not prohibited to the states) to the states or the people. It is a residual category, not a specific list.

2. Name the three types of preemption and give one distinguishing feature of each. Answer guidance: Express preemption (statute explicitly says it preempts state law), field preemption (federal scheme so pervasive it implies exclusive federal occupation, e.g., immigration), conflict preemption (compliance with both is impossible, or state law obstructs federal purpose).

Understanding

3. Why did the Supreme Court's Wickard v. Filburn (1942) decision dramatically expand federal power? Answer guidance: It held that even purely local, non-commercial activity (wheat grown for personal use) could be regulated under the Commerce Clause because, if aggregated across all similar farmers, it would affect interstate commerce. This "aggregate effects" reasoning let Congress regulate almost any economic activity.

4. What is the anti-commandeering doctrine, and what does it mean for states that don't want to enforce federal law? Answer guidance: Established in New York v. United States (1992) and Printz v. United States (1997), it holds Congress cannot force state legislatures to pass laws or state officers to enforce federal programs. States (or localities, like sanctuary cities) can lawfully decline to help enforce federal law, though the federal government can still enforce that law itself and may condition some grants on cooperation.

Application

5. A state passes a law requiring all local police departments to detain and report suspected undocumented immigrants to federal authorities upon request, while a neighboring state passes a law forbidding local police from asking about immigration status at all. Can the federal government force either state to change its policy? Answer guidance: No — under the anti-commandeering doctrine, the federal government cannot compel either state's police to actively assist federal immigration enforcement or to ask about immigration status. It can enforce immigration law itself and can potentially condition certain discretionary federal grants on cooperation, but it cannot issue a direct order to state or local police.

6. Congress passes a law regulating carbon emissions from power plants nationwide, citing the Commerce Clause. A state argues this violates its reserved powers under the 10th Amendment. How would a court most likely analyze this? Answer guidance: The court would first ask whether emissions regulation is an "economic activity" substantially affecting interstate commerce (very likely yes, given energy markets cross state lines) — similar reasoning to Heart of Atlanta Motel. If the law is a valid Commerce Clause exercise, the Supremacy Clause makes it binding on the states regardless of the 10th Amendment claim, because the 10th Amendment only reserves powers not given to the federal government.

Analysis

7. Compare dual federalism and cooperative federalism. What historical event triggered the shift between them, and why? Answer guidance: Dual federalism (1789–1937) kept federal and state spheres largely separate, with a narrow Commerce Clause. The Great Depression and the New Deal (1933 onward) triggered the shift — the crisis was too large for states to handle individually, and the Supreme Court, after initially striking down New Deal programs, eventually upheld broad federal regulatory power (post-1937 "switch in time"), ushering in cooperative federalism built on grants-in-aid.

8. Some scholars argue that conditional federal grants (as in South Dakota v. Dole) let Congress achieve indirectly what the anti-commandeering doctrine forbids it from doing directly. Evaluate this argument using NFIB v. Sebelius (2012) as a limiting principle. Answer guidance: Strong argument — Congress cannot order states to raise their drinking age, but it can condition a relatively small percentage of highway funds on doing so, achieving practical compliance without direct command (Dole, 1987, upheld this as non-coercive). NFIB v. Sebelius (2012) shows there is a limit: threatening to revoke all existing Medicaid funding for a state that didn't accept ACA's Medicaid expansion was unconstitutionally coercive — the "financial inducement" had turned into a "gun to the head." Students should discuss where the line between inducement and coercion falls and why the Court has left it somewhat vague.

FAQ

If federal and state law disagree, does federal law always win? Only when the federal law is a valid, constitutional exercise of federal power and there's a genuine conflict. The Supremacy Clause (Article VI) makes such federal law supreme, but if Congress lacked constitutional authority to pass the law in the first place, it has no special claim over state law. In areas the Constitution doesn't address, states retain full authority.

Why can states legalize marijuana when it's still illegal under federal law? This is a preemption and enforcement question rather than a legality one. Federal law (Controlled Substances Act) does preempt state marijuana legalization in the sense that federal marijuana offenses remain federal crimes regardless of state law. But the federal government has largely chosen not to enforce federal marijuana law against individuals complying with state law, creating a practical (not legal) coexistence. This could change if federal enforcement priorities shift.

What's the difference between a categorical grant and a block grant? A categorical grant is federal money tied to a specific, narrowly defined purpose with detailed conditions (e.g., funds only for highway construction meeting federal safety standards). A block grant is federal money for a broader purpose (e.g., community development) with much more state discretion over how to spend it. Categorical grants give the federal government more control; block grants give states more flexibility.

Can the federal government force a state to expand Medicaid or enforce immigration law? No, not directly — the anti-commandeering doctrine forbids Congress from ordering state governments to adopt or enforce federal policy. It can offer funding incentives (as with Medicaid expansion), but NFIB v. Sebelius (2012) held that threatening to cut off all existing Medicaid funding for non-compliance was unconstitutionally coercive. States can decline the expansion and keep their existing funding.

Is the Commerce Clause basically unlimited at this point? Not quite, though it comes close. After Wickard v. Filburn (1942), Congress could regulate almost any activity with even a marginal aggregate effect on interstate commerce. But United States v. Lopez (1995) drew a real boundary: Congress cannot regulate non-economic activity (like carrying a gun near a school) merely by asserting some indirect effect on commerce. The clause is broad but not boundless.

Quick Revision

• Federalism divides power between national and state governments, both deriving authority directly from the Constitution (dual sovereignty)
• Enumerated powers belong to the federal government (Article I, Section 8); reserved powers belong to the states (10th Amendment); concurrent powers (like taxation) belong to both
• The 10th Amendment is a residual clause, not a specific list of state powers
• The Supremacy Clause (Article VI) makes valid federal law supreme over conflicting state law — but the federal law must itself be constitutional
• The Commerce Clause is the main basis of modern federal regulatory power; Wickard v. Filburn (1942) let Congress regulate even purely local activity with an aggregate effect on interstate commerce
• United States v. Lopez (1995) was the first case since 1937 to limit the Commerce Clause — Congress cannot regulate non-economic activity
• Preemption comes in three forms: express, field, and conflict
• The anti-commandeering doctrine (New York v. US, 1992; Printz v. US, 1997) bars Congress from ordering state legislatures or officers to enforce federal law
• Cooperative federalism uses grants-in-aid — categorical grants (specific, conditioned) and block grants (broad, flexible) — to influence state behavior
• South Dakota v. Dole (1987) allowed conditional federal funding (drinking age); NFIB v. Sebelius (2012) held that overly coercive conditions (full Medicaid funding at stake) go too far
• Federalism has evolved from dual federalism (1789–1937) to cooperative federalism (1937–1990s) to New Federalism (1990s–present)
• Current federalism flashpoints include marijuana legalization, sanctuary cities, post-Dobbs abortion policy, and state environmental standards

Related Topics

Prerequisites: The US Constitution and Founding (enumerated powers, the Supremacy Clause, the Bill of Rights), basic structure of the three branches of government

Related Topics: The Three Branches of Government (how Congress exercises enumerated powers and courts adjudicate federalism disputes), Civil Rights and Liberties (how the 14th Amendment shifted power toward the federal government), Constitutional Law and Landmark Supreme Court Cases

Next Topics: State and Local Government structure, the Legislative Process (how conditional federal funding gets attached to bills), Contemporary Policy Debates (marijuana, immigration, abortion, and environmental federalism)