Ordinary Americans are deeply concerned about the nation's current level of immigration and consider it to be a threat to national security, but elite U.S. opinion leaders appear unconcerned, according to a new study. The Center for Immigration Studies, a non-partisan think tank that examines the impact of immigration on the U.S., said it found in its recent study that "an enormous gap exists between the American people and opinion leaders on the issue of immigration – a gap that seems to be increasing." "The gap between the opinions of the American people and their leaders on immigration is enormous,"...