Fast-forward to Covid-19. Federal law gives the president extraordinary power to implement a national pandemic response program if he determines that the states aren’t doing enough under the Public Health Service Act, among other laws. Were Trump to take such a step, a national contact tracing program that required infected individuals and their contacts to self-quarantine would likely satisfy Jacobson, which allows for nonarbitrary limits on individual freedom that are tailored to protecting public health. As the Jacobson court explained, “[e]ven liberty itself, the greatest of all rights, is not unrestricted license to act according to one’s own will.”

According to the CDC, contact tracing is a “specialized skill” that requires expertise in patient confidentiality, medicine, interpersonal skills and resourcefulness. For contact tracing to work, it is also important that the government maintain “engaged and supportive” communication with the public, as well as “agile data management systems to facilitate real-time electronic transmission of laboratory and case data for public health action.” We have none of this. All of it would benefit from a coordinated federal response.