The European Lisbon Treaty, approved by the European Council in October 2007 during the Portuguese presidency, opened a period of profound discussions about the reasons that led France and the Netherlands to reject in referenda the Constitutional Treaty presented to the population in 2005 as well about the new course that should be adopted in designing Union's new institutions. The present text summarizes the political-institutional debate that surrounded these two moments. This debate is affected by the incorporation of 130 million new European citizens from different origins and identities to the European Union territorial space, having a growing impact on political and economic resource distribution and on the perception of differences among the European population. Similarly to the normative debate, the cultural diversity will be examined in light of the main theories in the field of European studies.
European Union; Institutionalization; Enlargement; Identity; Diversity; Democracy