The real question is whether opposition is do to policies or skin color.
Were black people opposed to Bush because of his skin color or his policies?
Are white people opposed to ZerO due to his policies or his skin color?
With DumBO, he is half white, so, racism can be only half of it. The perception that only white people oppose ObozO is because so few blacks do. I have been to tea parties and town halls where the best arguments against ZerOcare were made by blacks and democrats.