What is the theme in An American Requiem by James P. Carroll?

Father and son conflict is at the heart of this story. James and his father have three areas of contention and conflict they cannot resolve; Roman Catholicism, civil rights and the Vietnam War. The child and young adult James is a devoted son and tries to follow in his father's footsteps by becoming either a priest or Air Force officer. He comes to a compromise by choosing to become an Air Force chaplain. Later reflection reveals he enters the seminary to please his parents and perhaps mitigate the Irish Catholic curse of Joseph's spoiled priesthood.