It's obviously a provocation. He's hoping the Republicans will oppose this bill so they can be accused of racism.
Many blacks have heard of Du Bois but don't really understand the meaning of his beliefs. They just know he was a noble black man, because that's probably what they were told in school.
No, it's a reciprocation!
After all, Kerry is honored by the Communists in the "War Heroes Museum" in Ho Chi Min City.