This research paper provides an extensive critical analysis of European Union public law, constitutional integration, and supranational administrative governance. Focusing on the Treaty on European Union (TEU), Treaty on the Functioning of the European Union (TFEU), and the jurisprudence of the Court of Justice of the European Union (CJEU), this study evaluates how EU legal institutions resolve constitutional conflicts between supranational supremacy and national legal identity. Furthermore, it examines the EU Charter of Fundamental Rights, digital regulatory frameworks (GDPR, AI Act, DSA/DMA), and rule of law enforcement mechanisms across Member States.