The present study of Basque polarized pluralism includes political attitudes, ethnic identity, and the support of terrorism. During the last 12 years Basque politics and society have undergone a solid process of consolidation for the autonomy institutions and their plurality. Juan Linz's central concerns about the Spanish transition was the breakdown of legitimacy in Euskadi in relation to the Spanish constitution and the Basque Autonomy Statute. Of the various forms of violence that occur in Euskadi, the authors are most interested in those initiated by ETA's radical nationalist terrorism, the cause of most of the violent deaths that have occurred in Spain over the last 30 years. By far the highest levels of ETA violence occurred during the period 1978-80, when the Spanish constitution and Basque autonomy statute were being negotiated and ratified, and the first elections to the regional parliament were being held.