I don’t know a single person on any end of the political spectrum who doesn’t want to see an end to police shootings of black folk. I don’t know a single person who doesn’t want to make sure that shootings like the Charleston one never happen again. But most ordinary white people also don’t have a clue how they could help with that, other than posting the occasional facebook meme or generally feeling it would be a good thing if something were done. Or maybe they’d like to do something, but ar...