With this past weekend’s loss by Louisiana Senator Mary Landrieu, the Republican sweep of the South is now complete. As the Los Angeles Times notes, “Democrats, starting in January, will not control a single governorship, U.S. Senate seat, or legislative chamber from the Carolinas to Texas.”

Most analysis of this trend echoes that of the Times reporter, who points out that “The realignment started as a backlash to the 1960s civil rights movement.” But recently published research suggests the channeling of racist attitudes into changed voting behaviors did not happen naturally, or automatically. Rather, it was due in part to the efforts of one organization: the Ku Klux Klan.

“Klan activism loosened entrenched party loyalties and directly contributed to the dealignment of white voters from the Democratic Party in the 1960s,” writes a research team led by sociologist Rory McVeigh of the University of Notre Dame. “This initial untethering process was critical to the more durable subsequent realignment with the Republican Party.”