The right isn't going after Obama because he is black, they are going after him because he is ideology different than they are. Same as when the left did that to Bush. Is it right to do that? Of course not, but racism is not in play for the majority.
Do you REALLY think that the right would do anything differently if Obama was white? No, they wouldn't. Race has nothing to do with this as a whole. Yes, there are some that don't like Obama because he is black, they are a minority.