United States v. Lopez in AP US Government

How far the Commerce Clause had stretched before 1995

The Commerce Clause (Article I, Section 8) gives Congress power to regulate commerce "among the several States." In Gibbons v. Ogden (1824), the Court read "commerce" broadly to include navigation between states.

After the New Deal, the Court let Congress use this clause for almost anything with some economic link. In Wickard v. Filburn (1942), a farmer growing wheat for his own farm was still covered, because millions of farmers doing the same thing would affect the national wheat market. In the 1960s, the Court upheld the Civil Rights Act of 1964 under the Commerce Clause in Heart of Atlanta Motel v. United States and Katzenbach v. McClung.

By the early 1990s, Congress was writing laws that were mainly about crime or safety and justifying them as commerce regulation. That's the backdrop Lopez reacts to.

A San Antonio senior, a handgun, and a federal charge

In 1992, Alfonso Lopez Jr., a 12th grader at Edison High School in San Antonio, Texas, brought a concealed handgun to school. Texas charged him under state law, but those charges were dropped when federal agents charged him under the Gun-Free School Zones Act, which made it a federal crime to knowingly have a gun in a school zone.

The question before the Court was whether Congress had the constitutional authority to pass that law under the Commerce Clause. The federal government argued that guns in schools lead to violent crime, violent crime raises costs that spread across the country, and unsafe schools hurt learning and the national economy.

Rehnquist's three categories and the line Lopez drew

Chief Justice William Rehnquist wrote the majority opinion. He said Congress can use the Commerce Clause to regulate three things:

• the channels of interstate commerce (highways, waterways)
• the instrumentalities of interstate commerce (vehicles, people and goods moving between states)
• activities that substantially affect interstate commerce

Gun possession near a school fits none of them. It isn't commercial, and the law had no requirement that the gun had ever crossed state lines. The majority pointed out that if the government's chain of reasoning were accepted, Congress could regulate nearly anything, including education and family law, and there would be no limit left on federal power.

The principle Lopez stands for is that enumerated powers have limits. Schools and local crime fall under the states' police powers, consistent with the Tenth Amendment's reservation of powers to the states. The four dissenters argued that Congress could reasonably connect school violence to the economy and that the Court should defer to that judgment.

What Lopez tells you about Topic 1.8

After Wickard and Heart of Atlanta stretched the Commerce Clause, Lopez is where the Court pulled it back. That shift is what Unit 1 (Foundations of American Democracy), Topic 1.8: Constitutional Interpretations of Federalism asks you to explain: how the Court's readings of the Constitution have moved power between the national government and the states over time. Lopez is the clearest example of an interpretation that shrank the Commerce Clause's reach.

The Court built on Lopez in United States v. Morrison (2000). Morrison struck down the part of the Violence Against Women Act of 1994 that let victims of gender-motivated violence sue in federal court, using the same reasoning: violent crime isn't economic activity. The trend had limits, though. In Gonzales v. Raich (2005), the Court upheld federal power over homegrown marijuana, relying on Wickard.

A multiple-choice question about Lopez could ask how the ruling affected the federal-state balance. The answer is that it limited Congress's Commerce Clause power and returned authority to the states. Don't confuse the ruling with an expansion of national power or a decision about Second Amendment rights.

Lopez against McCulloch, and against the Second Amendment

One easy mix-up is with McCulloch v. Maryland (1819), another required federalism case. McCulloch expanded national power by reading the Necessary and Proper Clause broadly and stopping Maryland from taxing the national bank. Lopez limited national power by reading the Commerce Clause narrowly. If a question asks how the Court has moved the federal-state balance in both directions, these two cases make that argument together.

Another mistake is calling Lopez a Second Amendment case. The Court never ruled on a right to carry guns. The ruling was only about which level of government gets to make the rule, and Texas could still punish guns in schools under its own laws.

Writing the SCOTUS Comparison answer with Lopez

Lopez is a required case, so it can be the required case in the SCOTUS Comparison question, where you get a summary of a non-required case and compare it to a required one. Commerce Clause cases like Heart of Atlanta Motel, Katzenbach v. McClung, Morrison, or Raich line up naturally with Lopez.

A strong answer names the shared provision (the Commerce Clause). It then explains why the outcomes match or differ. In McClung, the Court upheld the Civil Rights Act's application to a restaurant, reasoning that racial discrimination by restaurants, considered in the aggregate, affected interstate commerce. The restaurant also bought substantial amounts of food from out of state. In Lopez, possessing a gun near a school wasn't economic activity and had no comparable link to interstate commerce, so the law fell. Finish by connecting the result to federalism: the ruling either expanded national power or protected state authority.

In the Argument Essay, Lopez works as outside evidence for a thesis that the Constitution limits national power. It can also help you rebut a claim that Congress can regulate anything it ties to the economy.