bad blood lasts decades and centuries. You Americans whipped negroes to shreds, and now you're all offended "WHY are they angry with us D': we stopped whipping them! D': couple years ago D': WHAT DID WE DO WRONG!!!"
^Consequences.
We Norwegians haven't whipped anybody in 1000 years, but we DID decapitate Saami people untill only a century ago. And guess what. The Saami people still resent us for it. And guess what. We're being quite crude about it "Get over yourselves!" while still keeping Saami skulls in museums, like beasts, not fossil skulls, not archaeological artifacts, but murder victims, slayed by the Norwegian government, in order to shut them up, and stop them from rebelling.
So, yes, when a white American cop decides to pull out his belt, strap up a negro, and start whipping his back, people will react, because of old, bad blood.
But, you know, give it a couple of centuries, a thousand years perhaps, and it will level itself out, and people will get over it