The video 'BRI's Homework Help: U.S. v. Lopez' explores a significant legal case concerning the balance of power between state and federal governments. The main focus is on the U.S. v. Lopez case, which questioned whether Congress had the authority under the Commerce Clause to enforce the Gun-Free Zones Act, prohibiting firearms near schools. The case involved Alfonso Lopez Jr., a high school student charged for carrying a gun on school premises. The video details the legal journey from initial charges to a Supreme Court decision, highlighting the court's ruling that the Gun-Free Zones Act was unconstitutional as it overstepped federal powers, a critical issue in U.S. government and law. The 'Lopez' case is essential for understanding federalism and is particularly relevant for students learning about U.S. history and political science, emphasizing constitutional limitations and state sovereignty.