Many who write on race consider it an ‘illusion’. Others argue that race is real, even if socially constructed, because the notion of race, and the categorizing of people in terms of race, has greatly affected their lives. This paper criticizes a reason that is often given for thinking that race is an illusion: the fact that there is no biological basis of race. I defend two primary claims. First, while there is no biological basis for membership in a socio-economic class, by which I mean one's being relatively affluent or poor in a particular society, no one takes socio-economic class to be an illusion. Second, race is arguably a more fundamental reality than is socio-economic class. For one's racial identity can causally contribute to, and account at least partly for, one's membership in a socio-economic class. But membership in a socio-economic class does not thus contribute to, or account for, people's racial identities.