There's already community spread, it's too late to test only people who visited infected countries. Testing everyone, including asymptomatic people is not feas

There's already community spread, it's too late to test only people who visited infected countries. Testing everyone, including asymptomatic people is not feasible, there aren't nearly enough testing supplies (right now, California has 200 test kits for the entire state). And even if they had the supplies, finding the staff to do the tests is nearly impossible.