Basing on the Constitution of Russian Federation, constitutional law doctrine, Russian legislation and Russian Constitutional Court practice, this article considers the public authority system principles and explains their fundamental character. The constitutional reform of 2020 and its effect on fundamental principles of the public power system are being studied. The potential of the current Constitution is analyzed from constitutionalization perspective associated by the authors with the process of formal and legal consolidation of the existing system of public and power relations, which does not imply nevertheless a fundamental revision of the basic public power system characteristics. Constitutional consolidation and up-and-coming development of the implementation mechanism for fundamental principles of public authorities' management and operation in Russia guarantees that democratic state foundations are immutable. The scope of the constitutional principles of the Russian public authority system indicates their development towards the expended involvement of civil institutions in the state power mechanism work at all levels, as well as in local self-government. The Russian constitutional system of public authority principles promotes the development of the mechanism aimed at providing interaction of public authorities with one another and with public institutions. The main results found can be used in research practice in order to expand Russian constitutional law knowledge, and be applied in legislative and law enforcement practice. The study contributes mainly to scientific classification of public authority principles based on the analysis of changes introduced into the Russian Constitution of 1993 and existing approaches in the Russian legal science.