Saying the Democrats were the Southern secessionists ignores the revolt against civil rights in the 1950s and 1960s and the Southern Strategy [1]. All the Dixiecrats simply became Republicans.

Also, the slave owners who got strung up should probably have included Andrew Johnson. Without Lincoln's unfortunately untimely demise or without Johnson we may well have avoided Confederate leaders regaining power and the whole Redeemer era of winding back rghts for the former enslaved.

[1]: https://en.wikipedia.org/wiki/Southern_strategy