If anyone attempting to enter the United States indicates that he or she is "vehemently" opposed to Donald Trump, that person should be denied entry and their name should be placed on a watch list. No country should willingly admit anyone who is a potential threat to the country's leader. If those people who were turned back at the Canada-U.S. border feel that they have a right to travel to another country and express their hatred for its head of state, they should put their beliefs to the test in countries  like North Korea or Saudi Arabia. They might not be returning home for a long time, if at all.