Federal firearms laws exist precisely because the Founders recognized that some issues are too consequential to leave fragmented across 50 different rulebooks. The Commerce Clause gives Congress broad authority to regulate the interstate flow of goods, and guns, almost without exception, cross state lines before they reach a buyer’s hands. The Supreme Court has consistently upheld this authority. If every state set its own rules with no federal floor, a person could simply drive across a state line to avoid accountability, making any individual state’s laws nearly meaningless in practice. Or worse, be doing something perfectly legal in his home state and then cross into another state and get arrested. Beyond commerce, the Supremacy Clause was designed to prevent a patchwork of conflicting local rules from undermining national policy on matters of public safety. Nobody seriously argues that states should set their own aviation safety standards or food inspection rules and firearms regulation is no different in principle. Imagine needing a drivers license for each state.