Until the show hires a black woman. Via Business Insider:

Out of 16 “Saturday Night Live” cast members, currently only three are actors of color — Kenan Thompson, Jay Pharaoh, and the Iranian Nasim Pedrad.
So when the NBC comedy sketch show wants to do segments on pop culture hot topics such as Rihanna, Oprah, Michelle Obama, or Beyoncé, one of the black male actors is forced to cross-dress.
And Kenan Thompson, who has played everyone from Maya Angelou to Jennifer Hudson, has had enough.
Thompson opened up to TV Guide in a new interview, saying he will no longer dress as women on the show.
When asked what “SNL” will do now when confronted with potential black female characters or celebrity spoofs, Thompson revealed, “I don’t know. We just haven’t done them. That’s what I’m saying. Maybe [Jay Pharaoh] will do it or something, but even he doesn’t really want to do it.”

Even if SNL hires a black woman, I think the bits would be funnier with Thompson playing the woman than an actual woman playing the woman.

Additionally, Thompson is taking heat for adding that the reason that there isn’t a black woman on the cast is because “. . .in auditions, they just never find ones that are ready.”

And on another note, there are no Native Americans in the cast. Maybe somebody should ask Bob Costas to comment on that.