“The Turner Diaries” is a work of white supremacist agitprop. It purports to be the diary of a neo-Nazi militant, Earl Turner, who is working to overthrow the United States government — or as the book calls it, “the System” — through a group called “the Organization.” Turner castigates “the System” for promoting integration, encouraging nonwhite immigration and placing Jewish people, Black Americans and other minorities in positions of authority over whites.Among other atrocities, the novel describes nuclear attacks on predominantly Black cities, a Holocaust of Jewish Americans, the total ethnic cleansing of California, the subjugation of women and the...