FLU: Racism or charges of racism are the “third rail” in American society. Quickest way to shut someone down or shut them up is to accuse them of racism. I think the OP makes that point quite well. Any criticism of Obama, valid or not, can be dispelled instantly by ascribing it to racism.
The irony of course is that everybody, to a certain extent, is racist, consciously or unconsciously. Black people can be tremendously racist, especially when it comes to Asians and Mexicans. Asians can be racists, too, and even within their own racial group (have you ever heard Japanese people ripping on Koreans, Vietnamese and Chinese?).
The PC movement has destroyed free speech in this country and instilled a fear of saying anything that either gives offense or might give offense. It’s pathetic, really, but we’re all conditioned now.
I remember playing football in high school and having black players refer to me as Opie, Mickey, Cracker, Clem, Jethro, Honky and Whitebread, as well as some other epithets that aren’t repeatable. We treated it as part of the game and responded accordingly, using terms like Sambo, Toad and Jungle Bunny. The funny part? We all knew each other and got along with each other, when we weren’t on the field, that is. Using those terms openly today would get you sued.