A week before President-elect Donald Trump takes the oath of office, the U.S. Transportation Department issued new “guidance” for airline flight crews on how to avoid discriminating against Muslim and Sikh passengers. DOT said it recognizes the very important and difficult job of the airlines to provide a safe and secure travel environment. “At the same time, it is important that this function be carried out in a non-discriminatory manner.” The guidance says airline personnel must not be swayed by a passenger’s appearance alone: “In other words, airline personnel should ask themselves, but for the passenger’s perceived race, color, national...