In the US it's not clear the federal government actually has the power to order a nationwide shelter in place; "police powers" are typically reserved for the s

In the US it's not clear the federal government actually has the power to order a nationwide shelter in place; "police powers" are typically reserved for the states. The HHS/CDC can quarantine specific individuals or groups (with confirmation of infection) but I don't think can do this "in general". I think this one is up to the state governors who typically do have the power to do this through state health laws -- as has now happened in CA and undoubtably will happen in many more states over the next 48 hours.