If a US Customs and Border Protection officer doesn't feel good one?
If a US Customs and Border Protection officer is not feeling good, chances are he/she will call out sick and do everyone a favor by not bringing their germs into the work place. Otherwise, they have a set of standards they have to use to determine if someone can be allowed into the country or if they are to be denied. There is very little left to discretion between laws, policies, regulations and case law.