It was about states rights, but in a twisted way. FDR had courted the Southern Democrats back during the Great Depression, and it was a strange coalition of northern Progressive Republicans (yes, children, most Progressives WERE Republicans then) with the Solid South Democrats that got most of the New Deal through, including a considerable amount of clout delivered to the various industrial unions, (United Mine Workers, United Auto Workers, the AFL and the CIO), all much infiltrated with International Socialists (that is right, card-carrying Communists). The Unions had a sort of back-door deal, which they presented to the largely KKK members who were, incidentally, also the main force of the Southern Democrats. The KKK could keep their oppression of the black folk, and the unions would see that the blacks did not get hired by any industry, thus keeping them as virtual slaves, sharecroppers, down on the farm. In 1948, Harry Truman (together with Eleanor Roosevelt) made a BIG push for the blacks to be brought into the Democrat fold, with some of the first efforts at ending color separation, like ending segregation in the armed forces, and finding suitable post-war employment for the black veterans. This put the Southern Democrats at cross purposes with the industrial unions, who had broken their earlier promises to the regular corps of the KKK-Southern Democrats, and they revolted against the earlier coalition, forming the Dixiecrats, running their own candidate in the US Presidential race that year. The Dixiecrats were about as much anti-Communist as anyone in the country, but with no home any longer in the Democrat party, one by one they began to drift to the Republican party irregardless of the animosity that permeated much of the South after the Civil War. But in changing to Republicans, they rediscovered the real essence of America, and some of the best Republicans today are from the southern states. There have been repeated attempts to claim that the old Dixiecrats also carried their support of the KKK and suppression of blacks and Jews into the newly revived and resurgent Southern Republicans, but those attitudes died with the Dixiecrats as they aged and fell prey to time.
Appreciate that. That helps clarify things a lot.