A beautiful movie star is cast in a beloved story. The character is fictional—she isn’t even fully human. Nonetheless, activists and purists insist that the actor is the wrong race. I’m speaking of Scarlett Johansson in Ghost in the Shell, the 2017 film adaptation of a popular Japanese manga series. Critics accused the movie’s creators of “whitewashing” the heroine, a cyborg whose physical form is entirely prosthetic and whose race and gender are, in fact, mutable. She’s implanted with the consciousness of a Japanese woman, but her memories have been suppressed and edited. The story is an examination of how unstable identity is, and how untethered it can be from the body. Yet for detractors, the politics of representation—the simple fact that Johansson isn’t Asian—overrode the power of the film’s philosophical inquiry. Audiences are willing to suspend all manner of disbelief in service of a good story—except, apparently, when it comes to race. Hence the controversy surrounding this year’s most anticipated movie, Christopher Nolan’s adaptation of The Odyssey. The director cast the Kenyan Mexican actor …