This paper explores the effect of norms—standards of conduct dictated by an identity—on white, American immigration attitudes. Results from a survey experiment show that when respondents evaluate immigrants who violate cultural norms, by speaking a non-English language and/or rooting for a foreign soccer team, respondents are less supportive of green cards for immigrants. Moreover, norm violations are consequential for tolerant, prejudiced, liberal, moderate, and conservative respondents. Valuing cultural norms is a shared and pervasive aspect of immigration attitudes, and targeting norms for inquiry brings into view the societal structure of opposition to immigration. However, norm violations affect green card support among liberals only in evaluations of Latino immigrants, and among conservatives only in evaluations of European immigrants.