Since 2009, more Mexicans have been leaving rather than coming to the USA; likewise, illegal immigration from Mexico has declined. Yet, immigration remains a hotly contested issue in the 2016 presidential election, with a seemingly marked increase in anti-immigrant policy and rhetoric, much of which is directed at immigrants from Mexico. In this paper, we seek to explain how individual ethnocultural and civic-based conceptions of what it means to be an American influence attitudes towards immigration. Past theoretical research on national identity has framed the effects of these dimensions as interactive but past empirical work has yet to demonstrate an important interaction between race and ethnocultural identity. Failure to account for these interaction effects has led to inaccurate assumptions about the levels of hostility towards immigrants and how widespread anti-immigrant sentiment really is. We demonstrate a clear interactive effect between identification as white and ethnocultural dimensions of identity and show that this effect has masked the root of the most ardent anti-immigrant sentiment. We also show that while there is a sizeable minority of the population that identifies as both white and have high levels of ethnocultural identity, a majority of Americans prefer to keep immigration levels at the status quo and have an identity that is balanced between ethnoculturalism and civic-based conceptions of identity.