Reality.
The fact that you are still talking in terms of slaves and slaveholders shows you are still mired in that ridiculous scenario. Go back far enough, and every one of us had ancestors that were owned by someone else. Get over it.
You show me a black man who is still blaming his situation on slavery, and I'll show you a failure who can't get past his own shortcomings and is looking for excuses, or worse, a thug who is looking to shake someone down for his own enrichment.
Many liberals set a much greater store on race than conservatives, almost to the point where skin color and ancestry override almost every other aspect of relations with other human beings.