Contemporary discourse on domestic immigration policy varies widely based on political affiliation, linguistics, and regional differences. This experimental study aimed to concurrently investigate three social psychological bases of attitudes towards unauthorized immigrants in the United States: political ideology, social labels, and social context. Participants were 744 adults, recruited from “New York Community College” (“NYCC”/urban) and “New Jersey Community College” (“NJCC”/suburban), who were randomly assigned to one of two experimental conditions: “illegal” vs. “undocumented”. Participants completed a scale measuring their attitudes towards unauthorized immigrants with the embedded label manipulation, followed by the General System Justification scale, and culminating with demographic items. Results demonstrated that whereas social context and political ideology both contributed significantly to the regression model, the social labels did not. Both high system justification and political conservatism predicted negative attitudes, but the latter effect was stronger for suburban students. Post-hoc analyses revealed a significant difference between suburban and urban students in the frequency of the social labels “illegal” and “undocumented” heard and seen among family members, friends, and the media. Implications are discussed with a focus on system justification as an explanatory theory for immigration attitudes, as well as contextual effects for it.