In March, when state and local governments began sweeping, comprehensive lockdowns in response to the emerging coronavirus pandemic, millions of Americans had an urgent constitutional question. Can they do that? Do governments have that much power to respond to an infectious disease? 

It was a logical question. After all, virtually every living American had grown up in the era after we’d largely conquered infectious diseases. It’s not that we didn’t get sick, or that (for example) flu seasons couldn’t get serious, but the idea of a disease ripping through our communities and killing hundreds of thousands of Americans in a matter of weeks was utterly alien to our experience. 

But it wasn’t alien to our national or constitutional experience. And indeed there exists a body of constitutional case law—dating back to the founding generation—that acknowledges the police power of states to respond to pandemics, including by  passing quarantine laws and “health laws of every description.” Perhaps the best example of the Supreme Court’s “pandemic” law comes from a 1905 Supreme Court case called Jacobson v. Massachusetts.

In Jacobson, the plaintiff challenged a compulsory vaccination requirement in the midst of a smallpox epidemic. The court ruled for the state. First it noted the “paramount necessity” of the state to provide for the “self-defense” of the citizens “against an epidemic of disease”: