The authors investigate self-reported voter turnout and ethnic political activity across four-plus generations of Mexican Americans. Using a 1999 national survey, multivariate results indicate that the likelihood of Mexican American voting increases largely in a monotonic manner across generations while participation in ethnic political activity begins to decline after having one parent born in the United States. These results raise the question of whether disadvantaged ethnic populations necessarily benefit politically from assimilating given that gains in voting that accrue across generations are accompanied by declines in ethnic political activity among later generations.