United States v. Lopez, 514 US 549 - Supreme Court 1995

Finally, Congress' commerce authority includes the power to regulate those activities having a substantial relation to interstate commerce, ie, those activities that substantially affect interstate commerce.

Congress has power to regulate "three broad categories of activity" under the Commerce Clause:(1) "the use of the channels of interstate commerce;" (2) "the instrumentalities of interstate commerce, or persons or things in interstate commerce, even though the threat may come only from intrastate activities;" and (3) "activities that substantially affect interstate commerce."

In sum, the Court concluded, "The possession of a gun in a local school zone is in no sense an economic activity that might, through repetition elsewhere, substantially affect any sort of interstate commerce."

—the Supreme Court of the United States held that the Gun-Free School Zones Act, which made it a federal offense for a person knowingly to possess a firearm at a place that the person knew or had reasonable cause to believe was a school zone, exceeded Congress's Commerce Clause authority, because possession of a gun in a local school zone was not economic …

—the Supreme Court held that the Gun Free School Zones Act, 18 USC § 922 (q), exceeded Congress's authority under the Commerce Clause.

"Where economic activity substantially affects interstate commerce, legislation regulating that activity will be sustained."

Finally, the Court noted that Congress had made no legislative findings that would allow the Court to evaluate Congress's judgment that the regulated activity substantially affects interstate commerce.

Courts may not "pile inference upon inference in a manner that would bid fair to convert congressional authority under the Commerce Clause to a general police power of the sort retained by the States."

Of late, this deference has been most manifest in decisions by the Court to invalidate federal laws seen as unduly intruding upon state criminal law prerogatives.

Under the theories that the Government presents in support of § 922 (q), it is difficult to perceive any limitation on federal power, even in areas... where States historically have been sovereign. Thus, if we were to accept the Government's arguments, we are hard-pressed to posit any activity by an individual that Congress is without power to regulate