You have to remember that, prior to Nixon's Southern Strategy, southern Democrats (AKA Dixiecrats) were the Tea Party of their day: racist, xenophobic, religious fundamentalists bent on socially regressive and theocratic policies.
The south remained solidly Democratic from 1865 to 1965, a legacy of the Civil War and Reconstruction. The only thing that got them to switch sides was because the butthurt of a Yankee Catholic giving civil rights to the n*****s was greater than the butthurt of a Republican giving them freedom in the first place.
Most people tend to forget that, from Lincoln to Teddy Roosevelt, the Republicans were the progressive party, and the Democrats were the Conservatives. It wasn't until after the Taft-Roosevelt split at the 1912 Republican National Convention in that the GOP started becoming the party of big business and fiscal conservatism. The progressives eventually migrated to the Democratic party, but this just exacerbated the existing split between the northern Democrats and the Dixiecrat faction. For much of it's history the Democratic party was as dysfunctional and fractious as the GOP is today - unsurprising, considering that the Tea Party, the Dixiecrats, and the Civil War era Know Nothings are basically different manifestations of the same ideology and encompass the same demographic.