Where is your proof that she isn't?
cmon guys, what kind of a childish spat is this
she is, no she's not, she is, no she's not
would you call Jay Leno a racist for backing a white candidate ? so, maybe Oprah is backing Obama because he is black, maybe she is backing him because she sees him as a good candidate, whatever the case, there is no evidence that Oprah has acted in a particularly racist way
The school in SA - she came, saw a need, and decided to help, that's just what she does, in fact that's what most celebs do - eminem gives millions to inner city development - because as he says that's where he comes from - fifty cent does the same - Angelina Jolie donates much of her money to charity, and the list goes on and on
so if Jolie builds a retirement home - is she being ageist
if eminem sets up a music school in Soweto - is he being racist
if fifty cent decides to set up a foster care center in Danville - is he being classist ?