The increasing number of residents and citizens with non-Western cultural backgrounds in the European Union (EU) has prompted the question of whether member states (and the EU as a whole) can accommodate the newcomers and maintain their free polities (‘liberal democracies’) running. The answer depends on how important – if at all – cultural groundings are to democratic polities. The analysis of a fascinating Habermas-Ratzinger debate on the ‘pre-political moral foundations of the free-state’ suggests that while legitimacy originates on the will of the citizens that conform the political community, liberal democracies might not be completely free from moral principles implicit in their political culture. This possibility has normative implications for the political future of the EU, particularly regarding immigration, integration and citizenship policies.