As for the poll, this was done several years ago across the US.
All racial groups, including blacks, said that blacks were the most racist group. In fact, more blacks said blacks were the most racist and any other race said blacks were racist.
I think it's because black are constantly told, by liberals and others, that black can never, ever be racist no matter what they do. This allows them to do things that no other group, but especially whites, can do.