State governments, by contrast, with some exceptions here and there, have responded to the emergency more skillfully and in a way that has won more public confidence. States have had four key advantages:

• Knowledge of resources. States know far more than Washington about available local resources, such as closed hospitals, and how to activate them. Thus the quick plans to convert convention centers in New York, Baltimore and Santa Clara, Calif., into temporary hospitals, and Maryland Gov. Larry Hogan’s idea of repurposing the state’s vehicle-emissions inspection centers for drive-through medical testing.

• Knowledge of hazards. In some states, tourist crowds and late-night revelers pose the most urgent danger of spreading the virus, while in others it’s church gatherings. States with dense, transit-dependent cities face one set of challenges; those at the hub of international air travel, another. States can tailor local policy emphasis and messages in ways that would elude or overcomplicate any federal plan.

• Knowledge of response priorities. After the federal government’s fiasco in failing to approve Covid-19 tests, Gov. Andrew Cuomo of New York made sure his state took the lead in rolling out testing. His instincts were proved correct when that testing confirmed New York City’s status as the hotspot of the U.S. outbreak.