The problem of legitimacy of political institutions and institutions of state power is considered. Various approaches to determining the legitimacy of government are analyzed, but the main emphasis is on the level of trust and what exactly reduces the level of trust in government institutions Emphasis is placed on the factors that affect the fall of trust and lead to crisis phenomena in the political environment and destabilize society in general. The points of view of M. Weber, R. Dworkin and A. Buchann on legitimacy are compared, which give rise to different views on political obligations and normative conditions. A crisis of legitimacy is a situation in which the legality of the existing social order is questioned and distrust of the existing government is openly expressed, which demonstrates the inability of the government to assure society of the necessity and optimal functioning of existing state institutions. The reasons for the delegitimization of power are determined (the lack of proper representation of the interests of social groups and sufficient vertical mobility in the political system in combination with social inequality), which ultimately lead to the radicalization of attitudes in society, the strengthening of the opposition and, in general, distrust of state institutions The methodology of the “Funnel of Causality allows to combine different levels of society and take into account the effects of the environment. First of all, the macro level (economic development, the influence of geopolitical actors, historical traditions,national mewntality etc.), radical economic changes, the development of civil society, the political activity of various social groups, the growth of crisis phenomena, as a result of radical transformation. Due to the fluctuating nature of the country's political development during the years of independence, revolutionary situations arose, and the very legitimacy of the government, even at the macro level, was called into question.