It was designed to placate the slave states so they would enter the union. It is known.http://time.com/4558510/electoral-college-history-slavery/ In the beginning they allowed 5 slaves to = 3 votes. that was also a way to give more power to the slave states but not provide equality to blacks. The Repubs still don't want to let blacks vote.
Strange that the democrats (who were the proponents of slavery) are now charging history with being racist white right wing bigoted slave owners. FYI: the slave industry is still alive and well, the plantations have simply been moved to the inner cities of large liberal cities. Yep....it was the REBUBS that filibustered the CIVIL RIGHTS ACT, it was the REBUBS who created JIM CROW, the KKK, and fought against the right of minorities and female citizens to vote and own property...…
READ A DAMN HISTORY BOOK ON OCASSION.

One question: What party was represented by a former KKK leader up until as late as 2010? Robert KKK Byrd?
Why? Because the majority of the industrial jobs moved south. It did not have a damn thing to do with slavery or the color of anyone's skin.