The last time poetry saw this kind of action was with the cable knit sweater-clad poet and singer-songwriter Rod McKuen, who sold millions of books and millions more albums in the late 1960s and early 1970s with titles like “Listen to the Warm” — far outstripping the reach of not only an artist like Leonard Cohen, but most popular novelists of the time. (There were dusty McKuen books and records in my house growing up.) The backlash then makes today’s seem gentle