Holding and Rule (Justice Rehnquist)
1. The GFSZA exceeded Congress’ authority under the Commerce Clause.
2. The three broad categories of activity that Congress may regulate under its commerce power are:
a)The use of the channels of interstate commerce;
b)Congress is empowered to regulate and protect the instrumentalities of interstate commerce, or persons or things in interstate commerce, even though the threat may come only from intrastate activities;
c)Congress’ commerce authority includes the power to regulate those activities having a substantial relation to interstate commerce, i.e., those activities that substantially affect interstate commerce.

Education is a traditionally local government activity, and while education undoubtedly has an economic aspect, the nexus between regulating gun violence and the Commerce Clause power to regulate interstate commerce seems particularly strained. In Wickard v. Filburn, the Court ruled Congress was exercising its Commerce Clause power to regulate local economic activity in ways that the States were powerless to regulate, because only the federal government could effectively control the national wheat supply. The Court reasoned that if Wickard could be applied to acts of gun violence, simply because crime negatively impacted education, Congress might conclude that crime in schools substantially affects commerce, and may be regulated. Under this logic, all police power could be nationalized and local police and criminal courts eliminated on the theory that all crime has an impact on commerce.