It doesn't matter that they have no knowledge of or connection to a tribal culture. That most of their "blood" is non-Indian, they identify themselves as non-Indian, and they spend their lives immersed in the non-Indian world. Somewhere in their non-Indian DNA, a few nonstandard strands make them Indian.
According to the NativeCelebs fans, this tiny amount of Indian blood qualifies them to assume Indian roles. So we have Johnny Depp playing Tonto and Taylor Lautner playing Jacob Black. It also qualifies them to talk and act like (their version of) Indians. So we have Jessica Simpson claiming her right to say "Indian giver" and Miley Cyrus rocking her dreamcatchers.
Great. That's clear. Now let's apply the one-drop rule to another potential Indian:
Oprah has less Indian blood than Johnny Depp or Miley Cyrus, but more than Taylor Lautner or Jessica Simpson. When she was younger, Oprah proved her acting talent in several roles. Therefore, let's cast her in the next Hollywood movie as an Indian.
She's a bit too old to play Pocahontas or Sacagawea, but she can play the wife of a famous chief. Or Lozen, the warrior woman of the Chiricahua Apache. Or a modern Indian woman such as Wilma Mankiller.
Why not? She looks and acts as much like an Indian as the other performers I've named. She knows as much as they do about being an Indian. And most important, she has roughly the same small amount of Indian blood.
Does anyone doubt that Hollywood can and should cast Oprah as an Indian woman? If so, let's hear your case. Make sure you explain why it's not okay for Oprah to play an Indian, but it is okay for Depp and Lautner.
Good luck with your answers...you'll need it.
For more on Oprah, see Oprah to Visit Aboriginal Rock Art and Quileute Chairwoman Visits Oprah. For more on casting decisions, see New Spider-Man Is...White! and Denzel Washington as JFK?