Themes are the fundamental and often universal ideas explored in a literary work.
Chinatown suggests that the very notion of an honest, trustworthy leader is a myth. In Chinatown, people in positions of power are never what they seem to be, and their true nature is always harmful to the people beneath them. Cross, who has no official power but who has used his money to essentially run most of the city and the outlying area, uses the people he controls as pawns for his personal gain. The district attorney in Chinatown is legendary for his instruction that the police ignore any crime that is committed. Russ Yelburton, a polite, highly respectable family man, manipulates the public for personal gain and is involved in the slandering and murder of his boss. Even Lieutenant Escobar, a man whom Jake has worked with and respects, is willing to let injustice occur without punishing the people who brought it to pass. In the world of Chinatown, anyone with any authority becomes a mere cog in a machine that maintains corruption.
One basic element of the American dream is the idea that common people can move into unclaimed wilderness and transform it into valuable land. Water, and the irrigation systems that provide it, first helped the American West blossom into the rich and thriving area it is it is today. Cross calls Hollis Mulwray a genius for using water to help turn Los Angeles from a wasted patch of desert into an ever growing metropolis. Cross, however, turns this approach into an excuse for murder, killing Hollis when he interferes with Cross’s plans for the new reservoir. Similarly, Russ Yelburton is persuaded to betray both the public and a man he admires in order to gain greater control of the water.
Part of the allure of America is its promise of success for the common person, the chance to control one’s own destiny with the help of available resources. Cross, however, corrupts the American dream by stealing the most valuable of resources from the struggling farmers, pushing them into bankruptcy in an attempt to further line the pockets of his already rich associates. Chinatown shows the promise of America’s future betrayed by the desires of its corrupt present.
No matter how good a character is or how noble his or her intentions are, Polanski is careful to show how impossible it is for the common people to overcome or even escape the corruption that is so pervasive in the world of the film and the world itself. Unlike what Jake and so many other characters tell themselves, corruption isn’t confined to just one area. Jake, who years before lost a woman to evil forces in Chinatown, loses Evelyn in nearly the same manner. Evelyn, despite her money and earlier flight from her father, proves unable to run far or fast enough to escape death. Hollis, who tried to free himself from evil by cutting ties to Cross, nevertheless loses his life to his former business associate.