In all fairness to Spike (ughh, I feel dirty saying that) I don't see the above line as specifically telling Blacks not to vote for Rice. He seems to be saying don't vote for her just because of her race. I would agree with that as good advice for blacks and whites alike. Don't vote for or against anyone just becasuse of their race, rather, vote for the person you think will do the best job.
I have a feeling tho he only feels this way IF the person running for office is a conservative black.