Saint Oprah has always exploited race. She hasn't always done it crassly -- but if Oprah were white she would not have had the success she did. So much of it came to rely on her being an embodiment of the wise black woman archetype. In her early career where sheactuallyhad a show about womens issues it gave her credibility. In the middle of her career it gave her popularity and by the end of her career where she invited famous people to come jump on her couch and talk about how awesome they were... well, it didn't matter as much.
But watch the interview that Lucas had with Oprah where he's talking about his Tuskeegee Airmen movie. He sucks on her black tit so hard it's god damn shameful... and she puts it right out there telling him to suck it. All of her interviews were like that after she'd made a name for herself.
I respect early Saint Oprah. The rest... well, it just shows you the effect of money, fame, and influence. It'll drive anybody batshit.