Street protests across the United States and tense debates in the U.S. Congress have brought to the fore one of the unresolved issues of North American integration: migration. Proponents of the North American Free Trade Agreement (NAFTA) argued that by bringing wealth and jobs to Mexico, NAFTA would stem the flow of undocumented workers to the United States. Migration was therefore largely left out of the NAFTA agreement. However, Mexicans have continued to travel to the United States in large numbers and under increasingly dangerous conditions, despite U.S. attempts to police its border with Mexico. Migration has thus become a contentious and politicized issue that threatens to undermine the U.S.-Mexico relationship. Copyright