Americans' growing interest in, and aversion for, communism as an alternative to capitalism is central to Steinbeck's story of two Communist organizers in the California farming country. Steinbeck looks at what he has called the "human" side of communism: how the people who turn to communism as an answer to society's woes are accepted by others, why they are motivated to act as they do, and what impact they may have on others. As he does in The Grapes of Wrath (1939), Steinbeck deals ironically with the myth of the Promised Land: California appears as a paradise from afar, but within its gardens men must struggle to maintain bare existence. That circumstance gives Steinbeck opportunity to examine the social injustices magnified during the years of the Great Depression when thousands of migrant workers looking for a new start invaded California from Midwestern states.
In this book more than in any other, Steinbeck explores what he called the "group man" theory: the notion that groups are independent, "living" organisms in which the whole is greater than the sum of its parts. The story of the mob which the Communist organizers incite to strike and then to violence is the real focus of Steinbeck's novel; he is interested in why men band together, what they do when they give up their individuality to the group, and what it takes to form such organisms and keep them going.
(The entire section is 234 words.)