Langston Hughes, no doubt reflecting on his own wide-ranging political activities in and beyond Jim Crow America during the first half of the twentieth century, once described what he felt to be a central difference between the “social poet” and those poets who were more exclusively concerned with aesthetics and craft: “I have never known the police of any country to show an interest in lyric poetry as such. But when poems stop talking about the moon and begin to mention poverty, trade unions, color lines, and colonies, somebody tells the police.” Hughes’s crucial essay, published in W….