In Arkansas, at least, the Klan and the Democratic machine were synonomous after the assassination of GOP Congressional candidate John Clayton in 1880. Clayton was investigating the theft of a ballot box in the black town of Plumerville, a theft carried out by the Democrat Sheriff in response to an alliance between black republicans and white members of the Agricultural Wheel movement. The theft caused Clayton to lose the election. Many of the same Klansmen involved in that assasination were in the group C. Van Woodward described as delivering a contribution in full regalia during a church service he attended during his childhood in Russellville – all members of the local elite.
A few years back, the Arkansas Historical Quarterly published an analysis of membership roles and other documents that had been discovered for a southern Arkansas chapter of the 1920s Klan. Most of their membership consisted of “solid” middle and upper-middle class leaders of the community, and most of the activity at the time revolved around night-riding to enforce prohibition and supress prostitution. Interestingly, they were even willing (after some debate) to assist local black residents when it supported those activities. In contrast, the Klan and leadership of a white American Legion Post in Helena were involved in the murder of a number of black veterans and political activists post WWI when the local black community began to organizae politically to challenge the white elite. None of the night riders were punished, but several blacks who tried to defend themselves received lengthy prison terms of the death sentence – later commuted.
In the 1940s, the state elected a Governor, Homer Atkins, who was openly a member of the Klan. Atkins was involved in a number of unsavory incidents involving black soldiers training at Camp Joseph T. Robinson in North Little Rock and in threatening vigilante action if Japanese internees were allowed to seek jobs outside the camp.
Post WWII, establishment Democrat politicians, as opposed to reformers like Orval Faubus or Sid McMath retained Klan ties. The Hot Springs Machine, of which Bill Clinton’s maternal uncle was a part and which McMath tried to bring down, had strong ties to the Klan and to the Chicago Mob. Clinton’s mentor and Liberal Icon (for his anti-Vietnam statements) Senator Fulbright was a one-time Klansman and one of the movers of the Southern Manifesto. He was still an officious ass when I met him in the 1990s at an Arkansas Historical Society meeting. Part of the reason for Faubus’ actions during the 1957 Little Rock School crisis had todo with his trying to balance his position between the challenge of the threat of violence from establishment Democrat/Klan and the rising challenge from Republican Winthrop Rockefeller, who had the money to challenge the machine by paying the poll tax for black voters.