The "David" in this poem is David Horowitz. He was a leader of the New Left. His road away from it began when he recommended an idealistic lady he knew, Betty van Patter, as a bookkeeper for a black radical organization called "The Black Panthers". She discovered fraud in their finances, and shortly afterwards her dead body was found floating in the bay of San Francisco. The Black Panthers killed whites and blacks, but leftists liked their supposed ideas. The police thought that they were the culprits in the murder, and so did David. Anyway, that's the background for this poem.