Abstract Using correlational and experimental data, we examined the degree to which personal and perceived normative support for the acculturation ideologies of assimilation, multiculturalism, and colorblindness mediated and moderated the relationship between social dominance orientation (SDO) and prejudice among 299 White students at three American colleges. Correlational results indicated that personal support for the acculturation ideologies mediated the SDO–prejudice relationship. Personal support for assimilation (a hierarchy-enhancing ideology) positively related to SDO; multiculturalism and colorblindness (hierarchy-attenuating ideologies) negatively related to SDO. An experimental manipulation varied whether assimilation, multiculturalism, or colorblindness was considered normative in the United States. In addition to a control, a fifth condition primed the Obama presidency. SDO related most strongly to prejudice toward American immigrants and ethnic minorities when assimilation norms and the Obama presidency were primed. Efforts to reduce the associations between SDO and prejudice are discussed in terms of highlighting hierarchy-attenuating national norms of multiculturalism and colorblindness.