Mutual Trust and Constitutional Identity: Are there Limits to Value Pluralism in the EU?

The European Union has been a grand experiment in co-venturing. Member states united by a history of war and distrust have increasingly pledged over time not only to work together toward common aims but also to harmonize key features of their domestic political and legal orders. Now, however, both Poland and Hungary have mounted concerted political assaults on the rule of law and the independence of the judiciary in the name of a new illiberalism. Beyond those states, anti-system parties of the far-right have advanced in European elections across the continent in 2017, and have been kept out of governing coalitions by sometimes precarious arrangements. A growing number of constitutional courts have been asserting “constitutional identity” against the claims of the European Court of Justice that EU law is supreme over all national law, including constitutional law. Are there limits to value pluralism within the EU? What should European institutions do -- either about the growing dissent to the values espoused in Article 2 TEU by member states or about the radical redefinition of those values in illiberal parties that are coming closer and closer to power? Can the European Union adjust to living with growing assertions of value pluralism or must it find a way to restore common values?