Why has totalitarianism established itself in countries that have embarked on the path of democratic development?

Totalitarianism was often established not only in the countries of the East in Antiquity, but also in modern times. Often this happened after the country took the democratic path of development. Instability in the countries became the reason for the sharp change in the form of government. In a country in which power is exercised by the people, they often cannot come to a common decision. In recent democracies, power was fragile and could easily be overthrown by stronger parties. This is how the rule of fascist ideology was established in Germany.