Having worked as a farm laborer himself during the summers and other times he was away from college, John Steinbeck even lived with migrants in the farm’s bunkhouses in the Salinas Valley. Thus, his experiences often went into his narratives. Years later when he received the Nobel Prize for Literature, Steinbeck said,
“The ancient commission of the writer has not changed. He is charged with exposing our many grievous faults and failures, with dredging up to the light our dark and dangerous dreams for the purpose of improvement. Furthermore, the writer is delegated to declare and to celebrate man’s proven capacity for greatness of heart and spirit—for gallantry in defeat—for courage, compassion, and love. In the endless war against weakness and despair, these are the bright rally-flags of hope and of emulation. I hold that a writer who does not passionately believe in the perfectibility of man, has no dedication nor any membership in literature.”
After having witnessed first-hand the plight of the migrant worker and the disenfranchised, Steinbeck began to champion those who had been dispossessed by the Dust Bowl and the Great Depression. In his essay, The Novels of John Steinbeck: A Critical Study, Howard Levant writes that Steinbeck writes in The Grapes of Wrath of the conflict between law and anarchy,
The one idea postulates justice in a moral world of love and work, identified in the past with “the people” and in the present with the government camp and finally with the union movement, since these are the modern, institutional forms the group may take. The opposed idea postulates injustice in an immoral world of hatred and starvation. It is associated with buccaneering capitalism, which, in violent form, includes strikebreaking and related practices that cheapen human labor.
His leanings were socialistic and Steinbeck's novel was banned from many a library because of the exposure of this ideology as a solution to the plight of the Okies and other like them. The Grapes of Wrath, whose title comes from the song "The Battle Hymn of the Republic" is meant to inspire those who struggle against injustice, those who struggle against the Bank and against the forces of cold capitalism, such as the huge California farms. The Joads represent the group, the unit of strength that abides throughout, no matter the cost to them individually.