This study comparatively analyzes AI governance through the lens of multilevel constitutionalism (MLC) by contrasting two distinct regional models. The study proposes that there is a “thick” MLC in the European Union that provides coherent, supranational legal framework (e.g., the EU AI Act), ensuring multilayered rights protection at the expense of regulatory rigidity and potential democratic deficits. The “thin” MLC in East Asia is instead a fragmented, state-centric approach that allows for greater flexibility and policy experimentation by aligning with international soft law but struggles with cross-border accountability and regional enforcement mechanisms. The article concludes that the conversation about these divergent paths should focus not on superiority matters but on differences, arguing that the core of the future of digital constitutionalism lies in the mutual reinforcement of rights protections and transnational cooperation.