The paper stresses the fact that the European Union, despite the lack of a formal Constitution, is nevertheless already provided with norms that are substantially constitutional. Indeed, from a constitutional-law perspective it is possible to consider both Art. 2 TEU, setting down the EU shared values, and the Charter of fundamental rights, which – as is well known – with the entry into force of the Lisbon Treaty has been given the same efficacy of the Treaty itself. Therefore, the paper, focusing on what we might describe as the EU “constitutional core”, aims to show how its spreading and complete implementation throughout Europe would represent a unique and fundamental way to overcome EU citizens’ distrust on the project of a full political union. Furthermore, it would provide a strong guarantee for democracy and the rule of law even within those Member States’ legal systems in which these fundamental values currently appear to be threatened.