AbstractExplanations for the successful expansion and consolidation of the European Union and its legal system have long emphasized the importance of domestic courts’ sending preliminary references to the Court of Justice. Key to many of these theoretical accounts is the claim that domestic courts are better equipped than the Court of Justice to compel national governments to comply with EU law. Integrating insights from the comparative judicial politics literature into the context of the EU's preliminary references system, we provide a theoretical and empirical foundation for this claim by arguing that incorporating domestic courts into the EU legal process enhances public support for expansive judicial interpretations of EU law. We go on to argue, however, that this transfer of legitimacy depends on citizens’ views of the national and European courts. We support our argument with evidence from a preregistered survey experiment fielded in Germany.