Federalism

US Politics Fundamentals

Chapter 5 · Federalism: Real State vs. Federal Power

Chapter 1's own concept-grid described Article IV in a single line: defines state-to-state and state-to-federal relationships. This chapter goes underneath that Article to the real machinery that actually divides power between Washington and the fifty states — and closes with the sharpest possible contrast to UK Politics Fundamentals Chapter 9's own unitary-state material: unlike the UK's devolved powers, which Westminster could in principle claw back by ordinary law, a US state's own reserved powers are constitutionally guaranteed and cannot be stripped by Congress alone.

The Tenth Amendment: Reserved Powers, in the Constitution's Own Words

Ratified in 1791 as part of the Bill of Rights (Chapter 1), the Tenth Amendment states the federalism principle directly, in language that has barely needed interpretation since:

The Tenth Amendment, in full "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."

That one sentence sets up three real categories of power that recur throughout US government.

Enumerated Powers

Powers explicitly listed in the Constitution as belonging to the federal government — declaring war, coining money, regulating interstate commerce, and the rest of Article I, Section 8's own list.

Reserved Powers

Everything the Constitution doesn't delegate to the federal government and doesn't forbid to the states — under the Tenth Amendment, these belong to the states or the people. Policing, education, and most family law traditionally fall here.

Concurrent Powers

Powers both levels of government can exercise at once — taxation is the clearest real example: federal, state, and local governments all levy their own taxes independently.

The Elastic Clause: How Federal Power Actually Grew

Article I, Section 8 doesn't just enumerate Congress's powers — it closes with a clause letting Congress make any law "necessary and proper" for carrying those enumerated powers out. Real US history shows just how far that single clause has stretched.

McCulloch v. Maryland, 1819 — the same Chief Justice as Chapter 4's Marbury Maryland tried to tax the Second Bank of the United States — a federal institution nowhere explicitly named in Article I. Chief Justice John Marshall's ruling did two things at once: it held that Congress has real, genuine implied powers under the Necessary and Proper Clause, even for something (a national bank) never explicitly listed in the Constitution's own text — "it is a constitution we are expounding," Marshall wrote — and it held that Maryland could not tax that legitimate federal institution at all, since Article VI's own Supremacy Clause (Chapter 1) puts federal law above conflicting state law. Marshall's own famous line for why: "the power to tax involves the power to destroy." A state allowed to tax the federal government could, in principle, tax it out of existence.

The Commerce Clause: From Steamboats to a Single Farmer's Wheat

Congress's power "to regulate Commerce... among the several States" has been the single biggest real driver of federal power's growth relative to the states — and three landmark cases trace that growth with real, concrete facts.

Case	Year	Real facts	What it established
Gibbons v. Ogden	1824	A New York state steamboat monopoly blocked a federally licensed operator	Marshall's Court struck the state monopoly down — federal commerce power covers navigation, not just goods, and doesn't stop at state lines
Wickard v. Filburn	1942	A farmer grew wheat entirely for his own personal, on-farm use — never sold or shipped it anywhere	Upheld federal regulation anyway: enough individual farmers growing their own wheat, in aggregate, measurably affects the national wheat market — a dramatic real expansion of what counts as "interstate commerce"
United States v. Lopez	1995	A federal law banning guns near schools, challenged as exceeding Commerce Clause power	The first time in nearly 60 years the Court struck a law down as exceeding the Commerce Clause — carrying a gun near a school "has nothing to do with commerce" and wasn't part of any larger economic scheme

Finding: Wickard and Lopez are the two ends of the same real boundary Wickard v. Filburn shows the Commerce Clause reaching about as far as it has ever reached — regulating wheat a farmer never sold to anyone. United States v. Lopez shows the real, modern edge of that reach — after nearly six decades of federal power expanding under this clause largely unchecked, the Court drew a genuine line: something with no real connection to economic activity at all falls outside it. Both cases are still good law today; together they mark out roughly where the boundary actually sits.

Dual Federalism to Cooperative Federalism

The real historical trend since the country's founding — and especially since the Civil War — has been a steady shift of power away from the states and toward the national government. Early "dual federalism" treated federal and state power as two largely separate spheres, like layers of a cake that rarely touched. The New Deal era shifted the country toward "cooperative federalism" instead — federal and state governments jointly funding and administering programs together (Medicaid is a familiar modern example), with the federal government's own Commerce Clause and spending powers doing much of the work described above to make that shift constitutionally possible.

A Sharper Federalism Than the UK's Own Devolution

UK Politics Fundamentals Chapter 9 established the UK as a genuinely unitary state, with Chapter 7's own devolution material adding a real, important qualifier: Scotland, Wales, and Northern Ireland hold devolved powers, but Westminster itself retains full legal sovereignty over them — and the Sewel Convention, the norm that Westminster won't normally legislate on devolved matters without consent, is exactly that: a convention, real but not legally binding, which UK Politics Fundamentals Chapter 7 already showed being ignored 20 real, recorded times by February 2022 with no legal consequence.

	United States	United Kingdom
Source of sub-national power	The Tenth Amendment — states hold reserved powers as a constitutional guarantee	Acts of Parliament (e.g. the Scotland Act) — devolved powers are a legislative grant
Can the centre revoke it by ordinary law?	No — Congress cannot simply pass a statute stripping a state's reserved powers; doing so would require Article V amendment	Yes, in principle — Parliament remains sovereign and could abolish devolution by ordinary Act (UK Politics Fundamentals Ch.9)
What actually restrains the centre?	The Constitution's own text and judicial review (Chapter 4)	Political convention (the Sewel Convention) — real, but not legally enforceable

Finding: constitutionally guaranteed vs. politically protected This is the real structural payoff of everything this course has built so far. A US state's reserved powers rest on hard constitutional text (the Tenth Amendment) reinforced by judicial review (Chapter 4) — Congress genuinely cannot take them away without clearing Article V's own supermajority thresholds from Chapter 1. Scotland's devolved powers rest on Westminster's own continuing willingness not to override them — real, and rarely tested, but resting on convention rather than a legal wall the way the US Tenth Amendment does. Same underlying question — how much power does the centre share with its constituent parts — two structurally different real answers.

Hands-On Exercises

Exercise 1

Using McCulloch v. Maryland, explain what "implied powers" actually means, and why Marshall's ruling mattered for something (a national bank) that Article I never explicitly names.

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Exercise 2

Explain why Wickard v. Filburn is such a dramatic expansion of the Commerce Clause given that the farmer in that case never sold or shipped his own wheat anywhere at all.

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Exercise 3

Suppose the US Congress and the UK Parliament each wanted to strip a specific power away from, respectively, one US state and the Scottish Parliament. Compare what each body would actually need to do, and why the two processes are so different.

→ Solution

Quick Reference

Tenth Amendment (1791): powers not delegated to the federal government, nor prohibited to the states, are reserved to the states or the people
Three power types: enumerated (federal only), reserved (state only), concurrent (both)
Necessary and Proper Clause: the "elastic clause" — basis for implied federal powers
McCulloch v. Maryland (1819): implied powers upheld; states cannot tax legitimate federal institutions — "the power to tax involves the power to destroy"
Gibbons v. Ogden (1824): federal commerce power covers navigation and crosses state lines
Wickard v. Filburn (1942): even non-commercial, on-farm activity can be regulated via aggregate economic effect
United States v. Lopez (1995): first Commerce Clause law struck down in nearly 60 years — a real modern limit
Core contrast: US state powers are constitutionally guaranteed (Tenth Amendment); UK devolved powers rest on a revocable Act of Parliament and an unenforceable convention