Wikipedia:

The Nazi term Gleichschaltung (German pronunciation: [ˈɡlaɪçʃaltʊŋ] ^ⓘ) or “coordination” was the process of Nazification by which Adolf Hitler — leader of the Nazi Party in Germany — successively established a system of totalitarian control and coordination over all aspects of German society “from the economy and trade associations to the media, culture and education”.^[1] 

Although the Weimar Constitution remained nominally in effect until Germany’s surrender following World War II, near total Nazification had been secured by the 1935 resolutions approved during the Nuremberg Rally, when the symbols of the Nazi Party and the state were fused (see Flag of Nazi Germany) and German Jews were deprived of their citizenship (see Nuremberg Laws). The tenets of Gleichschaltung also applied to territories occupied by the Nazis. . .

. . .  Another measure of Nazi Gleichschaltung was the enactment of the “Law for the Restoration of a Professional Civil Service” (7 April 1933), which mandated the “co-ordination” of the civil service – which in Germany included not only bureaucrats, but also schoolteachers and professors, judges, prosecutors, and other professionals – at the federal, state and municipal level, and authorized the removal of Jews and Communists from these positions, with limited exceptions for those who had fought in the First World War or had lost a father or son in combat.^[19] . . .

. . . With Reich President von Hindenburg fatally ill, the Reich government enacted the “Law Concerning the Head of State of the German Reich” (1 August 1934). This law was signed by the entire Reich cabinet. It combined the office of Reich President with that of Reich Chancellor under the title of “Führer and Reich Chancellor,” and was drawn up to become effective on the death of the Reich President, which occurred the next day. Again, this flagrantly violated Article 2 of the Enabling Act, which forbade any actions interfering with the office of the Reich President. With this law, Hitler became not only Germany’s head of state, but also the commander-in-chief of the armed forces.[32] 

It also removed the last remedy by which Hitler could be legally removed from office, and with it all checks on his power.

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And of course:

One of the most critical steps towards Gleichschaltung of German society was the introduction of the “Ministry of Public Enlightenment and Propaganda” under Joseph Goebbels in March 1933 and the subsequent steps taken by the Propaganda Ministry to assume complete control of the press and all means of social communication. This included oversight of newspapers, magazines, films, books, public meetings and ceremonies, foreign press relations, theater, art and music, radio, and television.^[37] To this end, Goebbels said:

[T]he secret of propaganda [is to] permeate the person it aims to grasp, without his even noticing that he is being permeated. Of course propaganda has a purpose, but the purpose must be concealed with such cleverness and virtuosity that the person on whom this purpose is to be carried out doesn’t notice it at all.^[38]

This was also the purpose of “co-ordination”: to ensure that every aspect of the lives of German citizens was permeated with the ideas and prejudices of the Nazis. From March to July 1933 and continuing afterward, the Nazi Party systematically eliminated or co-opted non-Nazi organizations that could potentially influence people. Those critical of Hitler and the Nazis were suppressed, intimidated, or murdered.^[10]

Every national voluntary association, and every local club, was brought under Nazi control, from industrial and agricultural pressure groups to sports associations, football clubs, male voice choirs, women’s organizations—in short, the whole fabric of associational life was Nazified. Rival, politically oriented clubs or societies were merged into a single Nazi body. Existing leaders of voluntary associations were either unceremoniously ousted, or knuckled under of their own accord. Many organizations expelled leftish or liberal members and declared their allegiance to the new state and its institutions. The whole process … went on all over Germany. … By the end, virtually the only non-Nazi associations left were the army and the Churches with their lay organizations.^[39]

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