Andrew McCarthy reminds National Review Online readers that legal restraints require more than just the paper on which they’re printed.

Jim Geraghty posted about the decision by Dare County, N.C., to close its borders to non-residents. Is it merely a reaction, or an overreaction, to the coronavirus pandemic creeping across the nation?

The county’s move raises all sorts of constitutional questions about federalism. At what level of government do we properly resolve such questions — federal, state, county, municipal? Do Americans have a settled right of travel — intrastate, interstate, international — that applies at all times, or is the law flexible in this regard (as it can be regarding the imposition of martial law in times of war, invasion, and insurrection)? If a county can ban the entry of non-residents from its territory, can it ban the exit of residents, or at least of their property?

We could bat these questions around for some time. The bottom line, however, is that there are probably no settled legal answers. We miss that in normal times of peace and prosperity, when the rule of law governs. But in crisis, we see the limits of law. In essence, these questions call for political determinations. They turn on the perception of peril at a given time, which is a function of fluid circumstances that cannot be forecast with precision.

The law also works best when we are confident we know enough about a topic to regulate for all future conditions. The law works well for bank transactions, and especially for bank robbery. For infectious disease outbreaks . . . maybe not so much. …

… The history of this country is one of ceding authority to the chief executive, to an extent commensurate with the public’s sense of real threat, particularly lethal threat on a mass scale. Later, Congress and the courts push back, but only once the perception of peril ebbs.