Although the 14th Amendment of the U.S. Constitution grants American citizenship to any person born or naturalized in this country, subjective perceptions of who belongs in the country are driven by default assumptions that the prototypical American is White. This belief that Whites are somehow more American than members of other ethnic groups lies in sharp contrast to the widespread endorsement of multiculturalism in everyday life. Two studies provide evidence that these race-based beliefs about the prototypical American can produce discriminatory behavior against ethnic minorities in domains where patriotism is relevant, but not in domains where patriotism is irrelevant. Study 1 demonstrated that the more participants believe that the prototypical American is White, the less willing they are to hire highly qualified Asian Americans in national security jobs where patriotism is essential. Additionally, this effect was partially mediated by doubts about Asian Americans’ loyalty to thee country. Study 2 replicated and extended these findings by demonstrating that the more participants believe that the prototypical American is White, the less willing they are to hire highly qualified Asian Americans in national security jobs, but not in private business jobs where patriotism is irrelevant. Together, these studies demonstrate how race-based beliefs about the prototypical American can lead to discriminatory behavior against ethnic minorities, particularly in domains where national loyalty is important.