Too little, too late. This type of regulation made sense 2 weeks ago, combined with a halting of all international travel and an advisory against interstate travel.
The virus got out of control though. We don't know how many are infected, but we know our ground zero is 10-100x worse than the ground zero of nations that managed to get things under control.
People need to brace for impact. The US medical system is going to be overwhelmed by people in critical condition. The government has been too slow to respond.