What are the legitimate types of argument in constitutional debate? This is a perennial question in American law and every generation of constitutional scholars has the right to ask it anew. For over thirty years, Phillip Bobbitt’s taxonomy of legitimate constitutional argument types has reigned as the most influential and enduring in the scholarly discourse. In a recent article, Jamal Greene has proposed a welcome but flawed rhetorical re-conception of Bobbitt’s venerable typology. By identifying and correcting the errors in Greene’s framework, this Article provides a rigorous theoretical grounding for the entire constitutional law and rhetoric project. When properly grounded, constitutional law and rhetoric reveals how proof and persuasio...