The Ku Klux Klan's failure to defeat the black civil rights moment is well documented, but the group's lesser-known legacy may be its lasting impact on the U.S. political system, according to a paper published in the December issue of the American Sociological Review.

David Cunningham, professor and chair of the Department of Sociology at Brandeis University, Rory McVeigh of the University of Notre Dame and Justin Farrell of Yale University report that KKK activity played a significant role in shifting voters' political party allegiance in the South in the 1960s—from Democratic to Republican—and it continued to influence voters' activities 40 years later.

The researchers studied county voting records in 10 southern states in which the KKK actively recruited members in the 1960s. The analysis of five presidential voting outcomes, between 1960 and 2000, showed that southern counties with KKK activity in the 1960s had a statistically significant increase in Republican voting compared to counties with no established KKK chapter, even after controlling for a range of factors commonly understood as relating to voting preferences. They also found that conservative racial attitudes among voters in the 1992 election strongly predicted Republican voting, but only in counties where the KKK was organized in the 1960s.

"The Klan's efforts to link voting behavior to its social agenda in the 1960s disrupted long-established voting patterns in the South," Cunningham explains. "The fact that such efforts continue to predict partisan allegiances today demonstrates how the impact of a social movement can endure long after the movement itself has declined, as well as providing a new explanation of political polarization in the U.S."

Cunningham says their findings may have implications beyond providing a better understanding of how political agendas can have lasting societal impact. "Our research also illustrates how racial conflict can have wide-ranging effects that resonate across generations in ways that today's voters might not easily or directly recognize."

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