Open this photo in gallery: Senator Joseph McCarthy gestures during a Senate subcommittee hearing in Washington, D.C., on McCarthy's charges of communist infiltration of the U.S. State Department on March 9, 1950.Herbert K. White/The Associated Press Larry Tye is a journalist and the author of nine books, including Demagogue: The Life and Long Shadow of Senator Joe McCarthy. The Red-baiting lawmaker aimed wrecking balls at his enemies and at American norms. He railed against “enemies within” and crafted handy scapegoats for the country’s troubles. When one charge against a manufactured enemy was exposed as hollow, he would lob a fresh...