That is exactly right. They keep referring to "Southerners," as the villains in the fight for slavery. But nine of the thirteen states had slavery when the Constituton was ratified:
- Delaware
- Georgia
- Maryland
- New Jersey
- New York
- North Carolina
- South Carolina
- Virginia
- Connecticut
Five out of those nine were exactly states where the people ate corn pone and whistled Dixie during breaks from beating their enslaved farmworkers.
Whenever a Democrat says "southerner" in the discussion of slavery, mentally substitute "Democrat" because that is who they are talking about.