It upheld the principle that states have control of local issues, like gun possession on school grounds. Lopez was charged in a one-count indictment with violating 18 USC § 922(q), which makes it illegal to possess a firearm in a school zone.The supreme court sided with lopez in a 5-4 decision and here's the reasoning from the majority opinion. After the Lopez decision, the GFSZA was amended to specifically only apply to guns that had been moved via interstate or foreign commerce. The Commerce Clause, which grants Congress the power to regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes. The Tenth Amendment concerns the relationship between the federal government's powers and those powers reserved to the states. The Act neither regulates a commercial activity nor contains a requirement that the possession be connected in any way to interstate commerce. Maryland case in 1819, the Supreme Court said that the US Constitution and federal laws are more important than state laws. The Court's decision in Lopez adopted a more narrow interpretation of Congress's use of the. A case in which the Court found the 1990 Gun-Free School Zones Act unconstitutional for overstepping the congressional boundaries of the Commerce Clause.