This article addresses the relationship between the concepts of national identity and biopolitics by examining a border-transit camp for repatriates, refugees, and asylum seekers in Germany. Current studies of detention spaces for migrants have drawn heavily on Agamben's reflection on the “camp” and “homo sacer,” where the camp is analyzed as a space in a permanent state of exception, in which the government exercises sovereign power over the refugee as the ultimate biopolitical subject. But what groups of people can end up at a camp, and does the government treat all groups in the same way? This article examines the German camp for repatriates, refugees, and asylum seekers as a space where the state's borders are demarcated and controlled through practices of bureaucratic and narrative differentiation among various groups of people. The author uses the concept of detention space to draw a theoretical link between national identity and biopolitics, and demonstrates how the sovereign's practices of control and differentiation at the camp construct German national identity through defining “nonmembers” of the state. The study draws on ethnographic fieldwork at the Friedland border transit camp and on a discourse analysis of texts produced at the camp or for the camp.