The Supreme Court’s Commerce Clause jurisprudence has allowed Congress to change the nature of the federal government from one of enumerated powers into one of general powers. One can imagine pundits commenting on this case—“the Framers would be shocked to learn that the Commerce Clause gives Congress the power to regulate cock-fighting in Puerto Rico.” This brief proposes a restoration of the sound and principled basis for deciding Commerce Clause cases that gets beyond the clever arguments distinguishing or analogizing this case to precedents without a careful grounding in first principles of constitutional interpretation.