The expulsion of well over a million unregistered aliens from Nigeria in January 1983 abruptly conveyed to world opinion that the country was in the throes of a severe crisis. This chapter examines the shift to a mono-mineral export economy, the socio-economic proclivities of the dominant class, the considerable expansion in the state's economic role, and the distinct pattern of competition for access to public resources in all sectors of Nigerian society. An understanding of the vertical dimensions of political and social mobilisation in Nigeria can help explain why the dominant class in Nigeria is unable to rule effectively, even in its own interests. One of the greatest stumbling blocks in the analysis of contemporary African politics has been the zero-sum debate between class and ethnic models of social conflict. The chapter explains the notion of prebendal politics to refer the pattern of socio-political behaviour, and its attendant norms, whose features are now familiar to many students of contemporary Nigeria.