The Latino population has grown significantly over the last few decades in the United States and population projections suggest that the number of Latinos will increase disproportionately, relative to other immigrant groups, in the coming decades. These trends have resulted in great concern among some who fear that Latinos, especially Mexicans, are not acculturating and assimilating into mainstream, White America. Fears of the “browning of America” and of Latinos' presumed threat to the American way of life have led some to call for measures to ensure the preservation of America's national identity. Samuel Huntington is the latest public figure to make such claims. This paper provides an overview of Huntington's claims as well as the responses that his work has drawn from supporters and critics. Using data from the 2000 5% Public Use Microdata Sample, we assess the validity of Huntington's claims by examining the extent to which Mexicans, the largest Latino subgroup, have integrated into the United States, basing our assessment on a variety of selected demographic, social, and economic indicators. The results suggest that Mexicans have integrated in various dimensions, with the level of integration increasing with length of residence in the United States. We conclude with a discussion of the historical and contemporary context in which Mexicans have been racialized in the United States.