Participatory constitutionalism as the foundation of an adaptive constitutional model: doctrinal foundations and institutional challenges

Modern constitutionalism is undergoing a deep crisis of legitimacy, caused by the inability of traditional institutions to respond to the challenges of the digital age and the social transformations that accompany it. The accelerating pace of technological change, climate disasters, and global crises exacerbate the contradiction between the demand for constitutional stability and the necessity for rapid adaptation of the fundamental law. The growing deficit of civic engagement in constitutional processes undermines trust in legal institutions and creates systemic tension in society. The subject of the research is participatory constitutionalism as a theoretical construct that combines the principles of democratic participation, institutional flexibility, and constitutional stability. The article analyzes the mechanisms for transforming the constitution from a static text into an adaptive system capable of self-renewal through dialogue with society. Special attention is paid to the functional potential of civic participation in reducing "constitutional tension" and enhancing the legitimacy of legal innovations. The study examines both foreign practices (Ireland, France, Chile) and the Russian context, where institutions of direct participation face the problem of instrumentalization and lack of institutional guarantees. The research is based on a comprehensive application of theoretical-legal, comparative-legal, and systemic-functional methods, allowing for the analysis of the evolution of constitutional doctrines and institutional practices. The scientific novelty lies in the first systematic development of the concept of participatory constitutionalism in Russian legal science as an independent constitutional-legal construct, highlighting four key functions: legitimizing, innovative, stabilizing, and educational. For the first time, a theoretical distinction has been established between deliberative and participatory constitutionalism, where the former focuses on the quality of discussion while the latter emphasizes legitimacy through engagement. The study identified four systemic challenges to institutionalization: instrumentalization of participation, structural inequality, institutional inertia, and legal uncertainty, proposing principles for their overcoming. It concludes that participatory mechanisms can be adapted to the Russian reality not as an element of the Western model of checks and balances but as a tool for mobilizing society and strengthening public authority through horizontal connections. Participatory constitutionalism does not replace representative democracy but creates a synergistic ecosystem of legal flexibility alongside judicial interpretation and doctrinal adaptation. To overcome the legitimacy crisis, it is necessary to enshrine the principles of participatory constitutionalism at the constitutional level by establishing permanent institutions of civic participation and a secure digital infrastructure.