No joke: this is the 1956 Republican Platform:

[appmanga]

8. In that era, the Republicans were the "coalition" party...

...which relied on Northeastern and West Coast liberals, huge numbers of black voters, and the very rich. The only cohort to remain are the very rich, who may have been oppose to, and offended by LBJ's passing of the Civil Rights bill, but they knew they'd be alright. Southern Democrats, the reliable backbone of the party since the end of the Civil War were welcomed with open arms into a party they would spend the next 16 years converting into a comfortable home for racists, fascists, and anti-government demagogues.