Read the excerpt from Dr. Martin Luther King’s “Letter from Birmingham Jail.” The other force is one of bitterness and hatred, and it comes perilously close to advocating violence. It is expressed in the various black nationalist groups that are springing up across the nation. Why does the author include these sentences? to predict the future of his group’s actions to recall the harsh actions of law enforcement to encourage understanding of black nationalists to provide a contrast to his group’s nonviolent efforts