The answer to this question is so extensive and complex, most people would rather just give you a clue and hope you figure out the rest (I.E. Spurminator)
First of all, I understand where you are coming from. In an ideal world, race shouldn't matter.
Reality however, is not ideal, and racial discrimination is very real. It shouldn't come as a surprise to anyone that the black minority of America feels better represented by a black man, someone that is more likely to have lived their discrimination first hand, than by a white man. It doesn't really matter if it turns out to be true, the fact of the matter is it happens. Its not about whether or not it SHOULD matter (it shouldn't), but that it does.
Plus, anyone that knows anything understood that if there ever was a black president, the issue of race is something that would be unavoidable, as indeed it was in this campaign.
Now, just knowing about the history of the US should be enough to make you understand how momentous an occasion we're living here. To have a black president elected just 50 some odd years removed from Brown v. Board of education?? That is light speed social evolution man! Its something to be extremely proud of. , I'm not American and I'm proud of your achievement as a fellow human being.