I think the song is making fun of that article written by a black journalist. I personally don't find anything racist about the song. It might be dumb, but it isn't racist.
"negro" is no more racist than "honky" or "cracker". as far as i can tell, the singer is a negro. therefore, its existence is as racist as any song about "george bush: the magic honky"
edit: "george bush: the magic honky" would be sung by a white devil
Wait... are you saying that calling people "honky" or "cracker" is not racist?
they do have racist etymologies/origins from the era of american slavery.
since the singer of the barack song appears to be a negro, the use of the word "negro" within the song is not taboo. similarly, since i am a white devil, my use of the terms "honky" and "cracker" is not demeaning to those, like me, in a position of power.