This dissertation examines the current rule of law crisis within the European Union. It analyses the EU’s responses on the judicial-, institutional-, and financial level and places them into transatlantic perspective by drawing from similar constitutional challenges experienced in the United States federal legal order. By identifying common patterns and divergent approaches, this research offers insights into how the rule of law can be safeguarded in the Member States. The rule of law, a fundamental value of the EU and universal principle of democratic governance, is under threat in several Member States, with Hungary and Poland serving as prominent examples. This research examines the manifestations and implications of the rule of law crisis while drawing comparisons with similar constitutional challenges in the U.S. The impact on the institutional framework is assessed, shedding light on the erosion of democratic values and the challenges faced by the European integration project. Drawing on transatlantic comparisons, this dissertation explores the similarities and differences between rule of law challenges in the EU and the U.S. by examining constitutional case-law, institutional frameworks, and financial conditionality in both contexts. It provides valuable insights into the broader implications of rule of law backsliding in federal legal systems and its significance for democratic governance. Therefore, this dissertation follows a three dimensional approach: upholding the rule of law via judicial review through apex courts, upholding the rule of law via the political branches of government, and upholding the rule of law via financial conditionality. This dissertation provides a nuanced understanding of the constitutional challenges faced, enabling the identification of best practices and potential solutions. By identifying common patterns and divergent approaches, this research offers valuable insights for policymakers, legal scholars, and practitioners working to resolve the rule of law crisis and uphold democratic principles within the EU and beyond.