The Ku Klux Klan was originally focused on maintaining the old racial order in the postwar South, chiefly through the violent suppression of African-Americans. But, in the nineteen-twenties, the Klan was reborn as a nationwide movement, targeting not only African-Americans but Jews, Catholics, Muslims, Mexican-Americans, and Asian immigrants. In the jingoistic years following the First World War, the Klan made discrimination the new patriotism. The Bancroft Prize-winning historian Linda Gordon charts this rebirth in “The Second Coming of the KKK.” She writes that millions of people joined the Klan in the span of just a few years, among them mayors, congressmen, senators, and governors; three Presidents were members of the Klan at some point before taking the office. Gordon tells David Remnick that the lessons for our current political moment are sobering. The writer Andrew Marantz, who covers media and politics for The New Yorker, explains how today’s alt-right manipulates something called the Overton Window to bring fringe ideas into the mainstream. Plus, the staff writer Troy Patterson shares three recent picks with David Remnick.