You've been very polite and convivial to me here, and I suspect that you're probably quite a nice person on a personal level. That said, are you honestly that surprised to be called up on saying something akin to "Black people complain too much, so I want my own slaves"?
On a personal level, you're a nicer person than, say, Kowalski, but compared to him, some of your politics/views seem to be pretty shitty. You're like a polite/'nice' racist/bigot, whereas Kowalski is a like an asshole progressive/fair-minded liberal.
I have a saying - politics is politics. It means that discussion of recent events is a totally warlike arena. The first rule of war is manipulation. You cannot be precise or determinate about anything, especially if you have no clout to engage an effective change. Therefore it's a trivial endeavour to be invested in; those that do earn their suffering.
Furthermore, it is unlikely that many would object to observing Kowalski being aggressively whipped and forced to actually do something constructive for once....
I think there's something to be said for keeping politics out of other topics, and finding common-ground betweeen people of different political ilks, but there has to be standards and legitimising slavery is a line crossed way WAY too far.
Basic human-rights SHOULDN'T be a matter of 'politics'.