You sure can, it seems, judging by the response to remarks from Hillary Clinton:
"Dr. King's dream began to be realised when President Lyndon Johnson passed the Civil Rights Act of 1964,'' she had said. "It took a president to get it done.''
Her remarks were perceived by some US blacks as a suggestion that only a white president was able to translate the iconic civil rights leader's rhetoric into action.
Source
I see Hillary as an evil old witch with a cackle to suit but calling the above a racial slur is absurd.
