Constitutional law has helped make Americans unhealthy. Drawing from law, history, political theory, and public health research, Constitutional Contagion explores the history of public health laws, the nature of liberty and individual rights, and the forces that make a nation more or less vulnerable to contagion. In this groundbreaking work, Wendy Parmet documents how the Supreme Court departed from past practice to stymie efforts to mitigate the COVID-19 pandemic and demonstrates how pre-pandemic court decisions helped to shatter social contracts, weaken democracy, and perpetuate the inequities that made the United States especially vulnerable when COVID-19 struck. Looking at judicial decisions from an earlier era, Parmet argues that the Constitution does not compel the stark individualism and disregard of public health that is evident in contemporary constitutional law decisions. Parmet shows us why, if we are to be a healthy nation, constitutional law must change.