AbstractPeoples that span national borders are ambiguous in that they in some ways partake of both nations and in other ways partake of neither. This paper analyzes how the boundary ‐ the power to impose difference ‐ of the United States and Mexico is being eroded by transnational developments causing the structure of the nation‐states to become problematic. To the degree that anthropology is an official discipline predicated on the distinction between Self and the alien Other which it presumes to represent, the deterioration of the borders and boundaries of the nation‐state have serious implications for its epistemology and legitimacy and its power of representation of transnational communities and of difference in general. Furthermore, as national distinctions decline ethnicity emerges as a consciousness of dif