The guy who made the recording, that sings the song. The Reverend Al impersonator, he is black. He did it, he owns it as far as I am concerned.
I thought the whole deal is a parody or satire as the Reverend Al impersonator singing a song to Barack because he (Rev Al) is jealous of Barack because Barack is getting more attention than him (Rev Al)
Since a black dude made the recording I don't even think it was meant to be racist at all. It was supposed to be funny and IMO, it is kinda funny, I admit it, I laughed when I listened to it.
But really, even if a black man wrote, sang or distributed it, does it make it any less offensive. It cause quite the controversy when Limbaugh first played it and it hasn't diminished now. My father, thank goodness, always made sure from elementary school that I knew I was responsible for my own actions. I remember a teacher told my dad that some kids and I were singing an inappropriate ditty. He didn't seem impressed when I told him someone else started it. He held me accountable for my actions. So I tend to hold everyone else accountable for their actions and saying someone else started it just doesn't fly with me.