Why do the Liberals do it? Well, actual racist incidents (white against black, anyway) have become much rarer than they used to be -- and how can we continue to believe we're a racist society, if racist acts are so rare??
Liberals are just picking up the slack. For the children.
The Left has set up the legal machinery to prosecute people for "hate" crimes. Then the liberals themselves commit the "crimes" and try to frame or discredit the middle class white folks in America for being "racist." Or they pound the drums for even more stringent "hate" crimes laws. I've seen happen many times.