Howard W. Campbell appears in Kurt Vonnegut's best-known novel, Slaughterhouse-Five, in a minor role as "the American Nazi," a flashy, sophisticated propagandist for the Third Reich. In an earlier novel of Vonnegut's, Mother Night, Campbell is the protagonist, and explains how he came to be in this peculiar position. Ironically, it was his political apathy that led to his becoming embroiled in politics. He has lived in Germany since the age of eleven and simply failed to notice the Nazi Party coming to power. He joins the Nazi propaganda machine reluctantly to act as a double agent for the United States.

Campbell is very much in love with his wife, Helga, and they talk of living in a "nation of two," outside the world of politics and war. The novel, however, which ends with Campbell about to commit suicide in a prison cell in Israel, permanently separated from Helga, demonstrates that their romantic paradise is not an alternative to this harsher world. Even if you live in a nation of two with the one you love, you cannot escape living in a real nation as well, and that nation makes demands which are anything but idealized and romantic. One of the major themes of Mother Night is the way in which Howard and Helga Campbell's nation of two is invaded and conquered by the clash of the political nations they must also inhabit.