The Corruption of Revolutionary Ideals
Arroyo begins the revolution as a traditional revolutionary but it does not take long for him to begin to work towards his own personal interests rather than those of the people supporting him. Although he admits that he has the potential to become a dictator, and that the situation in the country is actually set up to enable him to do so, he does not seem to have realized that he is already exerting a dictatorial grip on the people. He wants to be in control of others at all time, and even when he is not, he manages to twist his own interpretation of the situation so that it can appear to him that everything is happening because he wants it to be that way. Ultimately his main goal is less about equality for everyone and a new power for the workers, and much more about getting his own revenge on the wealthy for whom he once worked. This plays into the theme of how easy it is for the theoretical ideals of a revolution to become corrupted.
Cultural Differences
Throughout the novel Mexico is seen as somewhere that needs to be civilized, and that the Mexican people are unable to bring civility to themselves. Harriet Winslow's view of the Mexicans is representative of this opinion; she is rather patronizing and feels that a good wash and some education would be far more beneficial to the Mexican people than taking up arms. Although she is not wrong about the benefits that education could bring, her observation also shows that she sees the locals as lacking in basic hygiene, and lacking in basic skills.
As the novel continues, Winslow starts to appreciate Mexico for its own identity and does not believe that it should be Americanized. She refuses to testify before Congress in this regard, however, the fact that there is a hearing at all about civilizing Mexico through a process of Americanization shows the way in which the nation was viewed at the time.