Difficulty: Intermediate | Prerequisites: Read the companion notes on Constitutional Foundations of American Federalism first. You should understand the basic structure of federalism, the Supremacy Clause, and the Tenth Amendment before tackling the case law here.
The Constitution sets out the rules, but the Supreme Court decides what those rules mean in practice. Since the early 1800s, the Court has been the primary arena where the boundaries between federal and state power are drawn, redrawn, and occasionally overturned. The cases covered here are the ones that shaped the structural relationship between the two levels of government. If you understand these rulings, you understand why federalism looks the way it does today, not just the way the Founders designed it on paper.
The Supreme Court acts as the referee of American federalism, deciding which level of government has authority over what. Early cases like McCulloch v. Maryland (1819) expanded federal power through the doctrine of implied powers, while later rulings such as United States v. Lopez (1995) pushed back by limiting Congress's reach under the Commerce Clause. The Court's interpretations have shifted the federal-state balance in every major era of American history.
Judicial review
The power of the courts to examine laws and government actions and declare them unconstitutional. Established by Marbury v. Madison (1803). In simple terms, courts get the final say on whether a law is allowed under the Constitution.
Implied powers
Powers not explicitly stated in the Constitution but inferred from the Necessary and Proper Clause. McCulloch v. Maryland (1819) is the landmark case establishing this doctrine. Think of it as: the Constitution gives Congress certain jobs, and implied powers are the tools it needs to do those jobs, even if the tools are not listed.
Commerce Clause
Article I, Section 8, Clause 3, which gives Congress the power to regulate commerce "among the several States." This clause has been the basis for vast expansions of federal regulatory authority, particularly since the New Deal.
Fourteenth Amendment (Section 1)
Ratified in 1868, it prohibits states from denying any person due process or equal protection of the laws. It has been used to apply ("incorporate") many Bill of Rights protections against state governments, significantly expanding federal oversight of state actions.
Incorporation doctrine
The legal principle by which the Supreme Court has applied most of the Bill of Rights to state governments through the Fourteenth Amendment's Due Process Clause. In simple terms, rights that originally limited only the federal government now also limit state governments.
Interstate commerce
Trade, transportation, and business activity that crosses state lines. The federal government's authority to regulate interstate commerce has been one of the most contested and expanded areas of federal power.
States' rights
The political position that favours limiting federal power and preserving the autonomy of state governments, grounded in the Tenth Amendment. Often invoked in debates about the proper scope of federal authority.
McCulloch v. Maryland (1819)
Issue: Could Congress charter a national bank, and could a state tax it?
Ruling: Yes to the first, no to the second. Chief Justice Marshall held that the Necessary and Proper Clause gives Congress implied powers beyond those explicitly listed.
Significance: Established that federal law is supreme over state law and that federal power can extend beyond the Constitution's literal text. One of the most important federalism rulings in U.S. history.
U.S. v. Carolene Products Co. (1938)
Issue: Could Congress regulate the interstate shipment of certain milk products?
Ruling: Yes. The Court upheld broad congressional power under the Commerce Clause.
Significance: Signalled judicial deference to Congress on economic regulation, reinforcing the shift toward cooperative federalism during the New Deal era. Footnote Four of this opinion also introduced the concept of heightened scrutiny for laws affecting "discrete and insular minorities."
Griswold v. Connecticut (1965)
Issue: Could a state ban the use of contraceptives?
Ruling: No. The Court found a constitutional right to privacy in the "penumbras" of several Bill of Rights amendments.
Significance: Extended federal constitutional protections into areas previously governed by state law, further demonstrating how judicial interpretation can shift the federal-state boundary.
United States v. Lopez (1995)
Issue: Could Congress use the Commerce Clause to ban guns near schools?
Ruling: No. The Court held that carrying a gun in a school zone was not an economic activity substantially affecting interstate commerce.
Significance: The first case in decades to limit Congress's Commerce Clause power. Reasserted that there are boundaries to federal authority.
Printz v. United States (1997)
Issue: Could Congress require state law enforcement officers to conduct background checks on gun buyers?
Ruling: No. The Court held that the federal government cannot "commandeer" state officials to enforce federal law.
Significance: Reinforced the principle that state governments are not mere instruments of the federal government.
Rapanos v. United States (2006)
Issue: How far does federal authority extend over wetlands under the Clean Water Act?
Ruling: The Court limited the scope of federal jurisdiction, requiring a clearer connection to navigable waters.
Significance: Demonstrated ongoing tension over the reach of federal regulatory power through the Commerce Clause.
The Supreme Court's role in federalism is to interpret the Constitution's distribution of power. As Brownell and Green (2009) put it, "the degree to which the Supreme Court defines federalism is the measure by which we understand the structural power relationship between the states and the federal government."
The direction of the Court's rulings has swung between expanding and limiting federal power depending on the era, the composition of the bench, and the political context.
The Fourteenth Amendment has been a particularly important tool, allowing the Court to apply individual rights protections against state governments through the incorporation doctrine.
Every time a federal regulation is challenged in court on the grounds that it oversteps Congress's authority, the legacy of these cases is at work. The Lopez ruling, for example, is why Congress now ties school-safety laws to federal funding rather than using the Commerce Clause directly. The Printz decision is why the federal government uses incentives (such as conditional grants) rather than direct orders to get states to implement federal programmes. When you hear debates about whether the federal government can mandate health insurance or regulate environmental standards, those arguments trace back to the Commerce Clause cases studied here.
Students often think the Supreme Court has always expanded federal power. It has not. Cases like Lopez (1995) and Printz (1997) explicitly limited what Congress could do, and the Court's direction has shifted across different periods.
Students sometimes believe McCulloch v. Maryland is only about banks. The banking question was the vehicle, but the real significance is the establishment of implied powers and federal supremacy, principles that apply far beyond banking.
The Commerce Clause is frequently misunderstood as giving Congress unlimited regulatory power. Lopez showed that there are limits: the regulated activity must have a substantial connection to interstate commerce.
Students sometimes conflate the Fourteenth Amendment with the original Bill of Rights. The Bill of Rights originally restricted only the federal government. The Fourteenth Amendment (and the incorporation doctrine) extended those restrictions to the states.
McCulloch v. Maryland is one of the most commonly tested cases in constitutional history courses. Know the holding (implied powers, federal supremacy) and be able to explain its lasting significance in one or two sentences.
Be prepared to compare a case that expanded federal power (McCulloch, Carolene Products) with one that limited it (Lopez, Printz). Exam questions often ask you to explain the tension between these rulings.
The Commerce Clause is a favourite exam topic. You should be able to trace how its interpretation broadened during the New Deal and was pulled back in Lopez.
Understand the incorporation doctrine well enough to give an example: the Fourteenth Amendment's Due Process Clause extending a Bill of Rights protection (e.g. free speech, right to bear arms) to the states.
True or False: McCulloch v. Maryland established that the federal government has only the powers explicitly listed in the Constitution. (False, it established implied powers)
Fill in the blank: The ______ Clause gives Congress the power to regulate trade between the states. (Commerce)
True or False: United States v. Lopez expanded Congress's Commerce Clause authority. (False, it limited it)
Fill in the blank: The ______ doctrine is the process by which Bill of Rights protections are applied to state governments through the Fourteenth Amendment. (incorporation)
True or False: In Printz v. United States, the Court ruled that the federal government can require state officers to enforce federal law. (False)
Q: What did McCulloch v. Maryland (1819) establish about federal power, and why is it significant for federalism?
A: It established the doctrine of implied powers, holding that Congress can take actions not explicitly listed in the Constitution if those actions are necessary to carry out its enumerated powers. It also affirmed federal supremacy over the states. This ruling gave the federal government far more flexibility than a strict reading of the Constitution would allow.
Q: How did United States v. Lopez (1995) change the trajectory of Commerce Clause jurisprudence?
A: Lopez was the first case in nearly sixty years to strike down a federal law for exceeding Congress's Commerce Clause authority. The Court ruled that carrying a gun near a school was not an economic activity with a substantial effect on interstate commerce. It signalled that there are outer limits to what Congress can regulate under this clause.
Q: Explain the anti-commandeering principle established in Printz v. United States (1997).
A: The Court held that the federal government cannot compel state executive officials to administer or enforce a federal regulatory programme. States are sovereign entities under the Constitution, not administrative arms of the federal government. This means the federal government must use its own agencies, or offer incentives, rather than ordering state officials to act.
Q: How has the Fourteenth Amendment affected the balance of power between federal and state governments?
A: Through the incorporation doctrine, the Supreme Court has used the Fourteenth Amendment's Due Process Clause to apply most of the Bill of Rights against state governments. This means states cannot violate rights such as free speech, freedom of religion, or the right to counsel, which originally restricted only the federal government. It significantly expanded federal oversight of state actions.
These cases sit on top of the constitutional framework covered in the companion notes on Constitutional Foundations of American Federalism. If you have not read those, start there. The Commerce Clause cases connect directly to the New Deal and the expansion of the administrative state, topics that typically appear later in American political history courses. The incorporation doctrine links to any unit on civil rights and civil liberties, since it is the mechanism by which the Bill of Rights constrains state governments.
Supreme Court federalism, judicial review, McCulloch v. Maryland, implied powers, Necessary and Proper Clause, Commerce Clause, United States v. Lopez, Printz v. United States, anti-commandeering, Griswold v. Connecticut, right to privacy, Rapanos v. United States, U.S. v. Carolene Products, Fourteenth Amendment, incorporation doctrine, due process, equal protection, states' rights, federal supremacy, constitutional interpretation, interstate commerce regulation, New Deal Supreme Court, Constitutional History US to 1865, ASU