"By writing black female protagonists into science fiction, and bringing her acute appraisal of real-world power structures to bear on the imaginary worlds she created, Butler became an early pillar of the subgenre and aesthetic known as Afrofuturism. (Kara Walker cites her as an inspiration; and, as Hilton Als has pointed out, Butler is the “dominant artistic force” in Beyoncé’s visual album “Lemonade.”) In the ongoing contest over which dystopian classic is most applicable to our time, Kellyanne Conway made a strong case for George Orwell’s “Nineteen Eighty-Four” when she used the phrase “alternative facts” and sent the novel to...