Were you looking in a mirror?
The antebellum South was solidly Democrat. Before the American Civil War, the Democrat Party was the dominant political force in the Southern states. This was largely because the party supported states' rights, including the right to maintain slavery, which was a critical issue for the Southern economy and social structure at the time. The Republican Party, which formed in the 1850s and opposed the expansion of slavery into new territories, had virtually no support in the South during this period.
This political alignment shifted dramatically after the Civil War and Reconstruction, but in the antebellum era, the South was indeed a stronghold for the Democrat Party.
@Grok