There are exceptions, but Republican leaders have been far more likely to resist the most aggressive social distancing measures, emboldened by President Donald Trump’s initial rosy outlook and a smaller early caseload in their more rural communities across middle America. But in the more crowded population centers on the East and West coasts where the disease first appeared, the Democrats in charge have been more willing to embrace strict steps such as curfews, sweeping business closures and law enforcement assistance.