This qualitative study examines how notions of sociopolitical membership and belonging are constructed in conversations about cultural difference. Drawing upon nine months of participant observation, informal conversation, and interviews with transnational youth at two U.S. high schools during the 2013-2014 academic year, my analysis highlights classroom conversations in which notions of "us" and "them" are delimited. These exchanges reveal tensions over the epistemic authority of teachers and how inquiry spaces of the classroom are constructed.