Jonathan J. Cooper/Associated Press

Florida Gov. Ron DeSantis canceled a day of presidential campaign appearances in South Carolina to deal with crises at home as his state mourns a racist fatal shooting in Jacksonville and prepares for a tropical storm.

The Biden administration is threatening to revoke the authority for three Republican-controlled states to handle their own workplace safety regulations because they have refused to adopt rules to protect health care workers from COVID-19. The threats were sent to Arizona, South Carolina and Utah as the U.S. Occupational Safety and Health Administration prepares to adopt much more far-reaching vaccination and testing rules affecting 80 million Americans.