As W. E. B. DuBois famously prophesied in The Souls of Black Folk, the fiction of the color line has been of urgent concern in defining a certain twentieth-century U.S. racial "order." Yet the very arbitrariness of this line also gives rise to opportunities for racial "passing," a practice through which subjects appropriate the terms of racial discourse. To erode race's authority, Gayle Wald argues, we must understand how race defines and yet...