Your point is not clear. There are no parties who supposed slavery today, so there's no point arguing it. The liberals you have such distaste for, were historically the northern Republicans including Lincoln. Now the names are different. They could have called themselves the purple and the orange party and it would not change this basic cultural/regional reality of US history.My minor was in post reconstruction U.S. history. I know all about the "re-alignment of the parties" I am just making a point.