In the 1942 case Tot v. United States, the Supreme Court upheld a federal law prohibiting felons from possessing firearms. Frank Tot Jr., who had been convicted of a felony in New Jersey state court, was later found with a firearm and charged under this federal statute. He challenged his conviction on constitutional grounds, arguing that Congress did not have the authority to regulate possession of firearms within individual states. The Supreme Court disagreed and ruled against him in an 8-1 decision. The majority opinion held that while there may be limits on Congress's power to regulate activities within states, those limits were not exceeded by this law because it served an important public safety purpose: preventing crime by keeping guns out of the hands of people likely to misuse them (i.e., convicted felons). This ruling has since been used as precedent for upholding other laws regulating gun ownership at both federal and state levels.

In the dissenting opinion for Tot v. United States, Justice Frank Murphy argued that the Federal Firearms Act violated the Tenth Amendment by infringing upon states' rights to regulate firearms. He contended that Congress overstepped its authority under the Commerce Clause because it did not sufficiently demonstrate a connection between interstate commerce and possession of a firearm by a convicted felon. Furthermore, he expressed concern about potential abuse of power if federal law could criminalize actions without clear ties to interstate commerce or other federal interests. The majority's interpretation, according to him, would allow Congress an unlimited police power which was never intended in Constitution's design.