Andrew McCarthy of National Review Online responds to President Trump’s suggestion that he might issue a quarantine.

The powers of the federal government in general, and of the president in particular, to quarantine American citizens are not cut-and-dried.

The Supreme Court has long recognized that citizens of the United States have a constitutional right to travel from state to state. …

… This right to interstate travel has three components: (a) the right of a citizen of one state to enter and leave another state, (b) the right to be treated as a welcome visitor while in another state, and (c) the right to resettle in a new state and be treated equally with the citizens thereof.

Of course, no right is absolute, even one said to be “virtually unconditional.” Congress, not the president, has the power to regulate interstate commerce. A federally imposed regulation on the right to travel between states may be upheld, even if the effect is to abide unequal treatment of citizens, if it is “shown to be necessary to promote a compelling governmental interest.” …

… To summarize, although American citizens have what has been interpreted to be a fundamental right to travel between states, the federal government’s very limited power to curb such travel undoubtedly includes authority to prevent the spread of infectious diseases — and COVID-19 certainly qualifies as one. Congress has the power to regulate interstate travel, and it has delegated that power to the executive branch for the purpose of protecting against the spread of infectious diseases.

Consequently, the president does have the power to restrict travel between the states of persons reasonably believed to be infected with COVID-19. I would assume that this means the power to prevent people who reside (or who have recently been present) in “hot spot” areas from traveling from those areas to other states.