The aim of my thesis is to investigate the possibility and necessity to rethink a constitutional framework and debate in a transnational polity such as the European Union. My effort focuses on a promising theory called deliberative constitutionalism, which carries on new insights on how democracy and constitutions relate each other. The EU is a unique political entity which poses unanswered questions about its political legitimacy and constitutional foundation, if a Constitution will ever be possible. Going beyond the classical conception of the national and sovereign ‘people’, we keep wondering how citizens may deliberate and discuss about their rights and political communities across borders, in what could be defined as a transnational ci...