Americans born before 1980, called Millennials, are repeatedly treated as a singular voting bloc, but much like the Baby Boomers, have been socialized across a series of very different elections. We develop a theory of millennial political socialization that argues that older Millennials are more tied to the Democratic party and more liberal than their younger counterparts. We use the 2016 Cooperative Congressional Election Study and an original survey of 1274 Americans conducted before the 2016 elections to test this theory. We find some support for our theory; in addition, we find that younger Millennials are socialized by issues of identity politics and culture – specifically on issues of immigration and the role of race in society. This implies a generation that largely favors Democrats, but whose Republicans are more culturally conservative than middle aged Republican voters.