This chapter will expose the several roles played simultaneously by the constitutional courts which make them ultimate players in multilevel constituent power games. The constitutional courts are gatekeepers of the bridge between the constitutionalism ‘within’ and ‘beyond statehood’. 2 They are safeguards, promoters, or limiters of constitutional nationalism, constitutional internationalism, constitutional supranationalism, and constitutional globalism. Last but not least, they are mediators of the participation of the member states in the European Union (EU). The analysis will be limited to the Bulgarian case not only due to space constraints, but also because of the principal need to broaden the analysis of the role of constitutional courts to less researched constitutional jurisdictions which do not actively engage in intense judicial dialogue with the Court of Justice of the EU (CJEU). The Bulgarian case requires attention because the jurisprudence and the general stance of the Bulgarian Constitutional Court (BCC) with regard to Bulgaria’s integration in the EU’s multilevel constitutionalism are still rather under-researched. Nevertheless, some good work has already been undertaken in that area. 3