The Supremacy Clause

The supremacy clause is a founding principle in U.S. constitutional law. It designates the Constitution as the "supreme law of the land." This generally means that when state laws conflict with the Constitution, the Constitution wins.

Supreme Court decisions have extended the supremacy clause also to include:

• Federal laws
• Federal regulations
• Federal treaties

For centuries, the supremacy clause has helped establish a strong federal government. Without it, some of the Framers of the U.S. Constitution feared we would be a nation in constant political chaos. States and the federal government would continually jockey for primacy, and America would not have the comfort of finality we now enjoy.

The Framers included the supremacy clause because the Articles of Confederation had no such clause. Under the Articles of Confederation, federal laws did not and could not supersede federal statutes and regulations.

Writing in the Federalist Papers, James Madison argued for the need for a supremacy clause. Madison recognized that state legislatures held all powers not explicitly given to the federal government under Article I and Article II of the U.S. Constitution. Therefore, he reasoned the supremacy clause was necessary to balance the scales of government.

What is the Supremacy Clause?

You can find the supremacy clause in Article VI, Clause 2 of the U.S. Constitution. It reads:

This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, 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.

What Does the Supremacy Clause Do?

The supremacy clause helps provide a balance between the federal government and state governments. In Federalist No. 44, Madison uses coining money as one example to illustrate the need for balance. He notes:

"[T]he same reasons which show the necessity of denying to the States the power of regulating coin, prove with equal force that they ought not to be at liberty to substitute a paper medium in the place of coin.

Had every State a right to regulate the value of its coin, there might be as many different currencies as States, and thus the intercourse among them would be impeded; retrospective alterations in its value might be made, and thus the citizens of other States be injured, and animosities be kindled among the States themselves."

In other words, chaos would ensue if each state had the authority to create its own currency. It could result in as many currencies as there were states and lead to unnecessary disputes. Ultimately, the supremacy clause assures us of finality in areas where federal law conflicts with state or local law.

The supremacy clause also provides boundaries for state courts. State courts cannot rely on a state law that conflicts with a federal law or statute.

History of Supremacy Clause

The inclusion of the supremacy clause was a reaction to the lack of such a clause in the Articles of Confederation. The Articles of Confederation were the first Constitution of the United States, approved by the Continental Congress in 1777. They provided the framework of the U.S. government from 1781 to 1789.

In practice, the Articles of Federation did not give the central government enough power to function. The central (federal) government lacked sufficient authority to:

• Regulate commerce
• Collect taxes
• Support a war

The central government tried to operate with minimal treasury funds during high inflation.

Against this backdrop, the Constitutional Convention assembled in 1787 to revise the Articles. Despite the controversies and debates over the supremacy clause during the Constitution's ratification, the Clause was ultimately included.

Early Supreme Court Decisions on the Supremacy Clause

In the decades following the ratification, the Supreme Court used the supremacy clause to establish the federal government's authority. Through Supreme Court decisions, the federal government was able to:

• Enforce the treaty ending the Revolutionary War
• Charter a central bank
• Enact legislation without interference from the states

We discuss two early Supreme Court cases on the supremacy clause below.

Ware v. Hylton

In 1796, the United States Supreme Court heard its first Supremacy Clause case: Ware v. Hylton. This case pitted a state law against a federal treaty. The laws at issue were:

• The Treaty of Paris, which ended the Revolutionary War between the United States and Great Britain
• A Virginia law that allowed residents who owed money to British creditors to discharge their debts

The Virginia legislature passed the law during the Revolutionary War, reasoning that debts owed to British subjects were owed to an "alien enemy." However, Article IV of the Treaty of Paris stated that creditors on both sides "shall meet with no lawful impediment" to recovering debts.

The Supreme Court invalidated the Virginia law, holding that federal treaties supersede state laws.

McCulloch v. Maryland

In McCulloch v. Maryland, the U.S. Supreme Court cemented the supremacy clause as the controlling authority in constitutional law. McCulloch set the standard we know today for conflicts between federal and State laws: the Constitution always wins. Federal law supersedes conflicting state laws.

Leading up to McCulloch, the Maryland General Assembly passed a law imposing a $15000 annual levy (tax) on any bank doing business in Maryland that was not chartered by the State. This was in direct opposition to the newly formed Second Bank of America. James M. McCulloch, the head of the Second Bank of America's Baltimore branch, refused to pay the tax. Maryland sued McCulloch.

The State of Maryland argued that since the Constitution is silent on the issue of banks, the federal government lacked the authority to find one. The lower courts sided with the State of Maryland, and the federal government appealed to the Supreme Court.

Ultimately, this case was about the division of powers, and the Supreme Court brought the thunder with its unanimous decision. The Court sided with the federal government, recognizing that Congress had the powers to pass laws necessary and proper to carry out its work.

Chief Justice John Marshall delivered the opinion of the Court, and he was clear that the Constitution grants Congress the authority to make all laws necessary to carry out its Constitutional duties.

Dual Federalism

During the latter half of the 19th century, the Court embraced dual federalism, which helped minimize conflict between federal and state officials. The Court recognized that the federal government and individual states could occupy zones of influence that didn't overlap.

There are some areas over which the federal government has exclusive control, like foreign policy and immigration. States, by contrast, have exclusive control over issuing driver's licenses. So, your state government cannot enter a climate change treaty with Uzbekistan, and the federal government cannot issue a state driver's license.

Types of Federal Preemption

Federal law expressly preempts state law when it contains explicit language to that effect. By contrast, federal law implicitly preempts state law when that intent is implicit in its structure and purpose.

Express preemption occurs when Congress clearly states that a federal law preempts certain kinds of state laws. For example, take the Airline Deregulatory Act of 1978 (ADA). In the text of this law, Congress "stipulates that the Federal Government shall have preemptive rights about interstate air transportation." This is an example of the federal government declaring its supremacy over one area of regulation. It left no room for doubt.

In contrast, there are several types of implied preemption, including:

• Field preemption: Where federal law is "so pervasive as to make reasonable the inference that Congress left no room for the States to supplement it" or where "the federal interest is so dominant that the federal system will be assumed to preclude enforcement of state laws on the same subject."
• Conflict preemption: Where compliance with both federal and State law is impossible ("impossibility preemption") or where state law poses an obstacle to federal objectives ("obstacle preemption").

The U.S. Supreme Court began developing its "field preemption" doctrine in the early 20th century and relied on it to make preemption decisions through the New Deal Era of the 1930s and 1940s.

In Pacific Gas & Elec. v. Energy Resources Commission, the U.S. Supreme Court resolved a conflict between a California law regarding nuclear power plants and the Atomic Energy Act of 1954. The Court recognized that the federal government "occupied" specific fields, like nuclear waste disposal technology and nuclear safety regulation.

The Court later expanded the areas where the federal government and states possessed authority simultaneously to balance the powers between the two. The Court articulated a presumption against preemption: federal law doesn't automatically replace state law. Now, federal law must articulate Congress' clear and manifest purpose.

Today, the supremacy clause is well-established throughout our judiciary. Litigants rarely directly challenge the meaning or application of it. Instead, supremacy clause challenges are a regular part of litigation.

Impact of the Supremacy Clause

Sometimes, it's difficult to imagine how laws created centuries ago can impact our daily lives. One important example is the use of the supremacy clause (and the commerce clause) to desegregate the American South. Katzenbach v. McClung is one such case that changed lives and propelled America toward equality.

Katzenbach v. McClung

In Katzenbach v. McClung, the Supreme Court held that the Constitution's commerce clause prevented a restaurant from refusing to serve Black customers. Katzenbach featured Ollies Barbecue, an Alabama restaurant that refused to serve Black customers. Ollies purchased 46 percent of its meat —a substantial amount—from a supplier that procured it from out-of-state.

Katzenbach built on cases such as Gibbons v. Ogden, where the Supreme Court held that Congress alone has the power to regulate interstate commerce. And as we've discussed, the supremacy clause means that federal law overrides state law.

Since a substantial portion of the food Ollies Barbecue served moved in interstate travel, Congress took the opportunity to step in under the Commerce Clause and prohibit racial discrimination in restaurants offering to serve interstate travelers or serving food where a substantial portion has moved in interstate commerce.

These types of cases, where attorneys general like Nicholas Katzenbach used creative and novel theories, helped systematically desegregate the South. Something as insignificant as meat purchase out of state brought justice to millions of Americans.