Just as FDR and his allies were crafting the New Deal, a retired Marine named Smedley Butler came forward with a shocking revelation. Powerful business interests, Butler alleged, were plotting to overthrow the U.S. government. Inspired by the rise of fascism in Europe, the conspirators had sought Butler’s aid. Little did they know, decades of fighting for American imperialism had left him disillusioned. So Butler blew the top on “the Business Plot.” Journalist Jonathan Katz helps unearth this bizarre tale.