James Madison wrote: " The accumulation of all powers, legislative, executive, and judiciary, in the same hands...may justily be pronounced the very definition of tyranny. "With the advent of the Administrative-Welfare State in 1933 vis the Emergency Banking Act, House Joint Resolution 192, The Social Security Act, and the culmination of programs that constituted " The New Deal", the executive branch of government has exercised ALL powers of the government in its various different administrative agencies. Administrative agencies generally have legislative power, as they possess the authority to establish rules and provisions that have the force of law. Administrative agencies also have executive power, because they are responsible for bringing enforcement action against those who violate the relevant federal laws and regulations. Finally administrative agencies frequently have judicial power in that they employ administrative law judges who hear cases brought by agency officials against those accused of violating the agency's regulations.
Under the guise of "National Emergencies" de facto government through the executive branch, exercises powers that supersede the de jure delegated powers (Article 2 constitutionally enumerated powers). This is the usurpation that's mentioned in the definition of de facto. Truthfully, governance by executive order and military occupation/domination started under Lincoln Administration with General Orders 100 aka the Lieber Codes.
The Emergency powers granted to the president/executive branch during "national emergencies" declared in 1933. This ensures perpetual extra-constitutional powers in the executive branch/president that allows tyrannical like administration through federal and state administrative agencies. What people perceive to be normal and proper governance is actually transference into total tyranny, totalitarianism, communism, etc.