The War of Northern Aggression was, mostly, about taxes and control. The slavery issue was a sideshow IMO.
As far as Dem vs Rebuplican on the issue, we can look to somewhat more recent history - and LBJ's infamous quote.
Exactly.
Of course, most school children outside of Dixie don’t learn this because the Lincoln myth propagators have completely ingrained their propaganda to a point that most non-Southerners accept it as Gospel truth.