"The purpose of this work is to explore the advantages and disadvantages of... Mexican immigrant workers for the economy and the political and cultural status quo of the United States. The Mexican immigrant workers pose a dilemma for the United States. On the one hand, the United States needs them for a better functioning of its economy. On the other, the Mexican immigrant workers represent a racial, cultural and political challenge to the American 'establishment'.... Given the magnitude of the problem which the Mexican immigrants represent and the intense debate surrounding it, the cheap labour they represent for the economy of the United States and the unsolved conflicts this provokes, are fertile ground for the analysis of the economic, political and cultural interests competing for the degree of flexibility or the amount of policing the Mexican border should have." (SUMMARY IN ENG AND FRE)