Are these idiots claiming that the Democrat party was NOT the party of slavery? 
A long time ago, I saw a dummie try to explain this.
Back then, ideologically, republicans were really democrats based on their philosophy.
Democrats were really republicans, so even though Lincoln was a republican, he was actually a democrat, then ideologies switched to the modern day and democrats changed to being republican and republicans changed to being democrats.
Therefore, democrats freed the slaves while republicans wanted them.
It's pretzel twisting logic that makes absolutely no sense other than to convince themselves THEY were not the party of slavery.