As if a group can complain against discrimination only if their pain is as big as another groups?

BBT as a minstrel show -- which is a way of mocking another group -- is an apt simile, regardless of whether blacks suffered worse fate or not.

Which is not even relevant anyway: what blacks suffered had little to do with minstrel shows, those were the least of their troubles. If parent had compared BBT to slavery, you'd have a point. But he made a much more precise argument.