Second Amendment Principles

In United States v. Rahimi, the Supreme Court explained that firearm regulations “must comport with the principles underlying the Second Amendment.” This Article examines what those principles are, how to derive them, and how to apply them in concrete cases. It begins with the Second Amendment’s core principle of defense of self and community, which traces its lineage back to classical thinkers like Aquinas and Grotius. The tradition of firearm regulation that surrounded the adoption of the Second Amendment depended on this fundamental principle. But it also developed subsidiary principles that implement the defense principle in specific ways. This Article analyzes a spectrum of these historical laws from the colonial through the antebellum periods and extracts the “principles that underpin our regulatory tradition.” While the Court’s explicit direction to rely on these principles is new, its entire line of Second Amendment case law, from Cruikshank to Rahimi, engages with them at some level. Implementing these principles as the Court has provides a robust framework for adjudicating contemporary Second Amendment challenges. This Article provides examples of how to apply these principles in cases involving concealed carry regulations, “assault weapons” bans, and felon-in-possession laws. And looking forward, this Article argues that courts need only grapple with the Second Amendment’s fundamental defense principle to understand the “historical tradition of firearm regulation” that now determines the scope of our Second Amendment rights.