It's abundantly clear that governors and mayors, not the federal government, have the broadest quarantine and isolation authority. That's because the Constitution leaves that kind of police power in the hands of the states.

Longstanding federal laws, and rules put in place at the end of the Obama administration, give the Centers for Disease Control and Prevention authority to quarantine people to stop disease outbreaks.

Broadly speaking, the CDC has the power to detain people suspected of having a communicable disease, without getting approval from state and local officials. However, that authority is rarely used, and when it has been invoked, it was directed at individuals and small groups.

So could it be used to impose a national quarantine? Experts on public health law say maybe, but an attempt to do so would likely be challenged in court.

For the full story, go to NBC News