I have to add what I forgot to write in my previous comment:

While a solid scientific understanding of the state of society we are acting in is a precondition of a successful revolutionary leadership, the political activity itself is rather an art, as Fidel Castro once explained.

In the concrete situation, the struggle for workers power emerges from the defensive fight against the rightist coup — the Kapp Putsch was defeated quite quickly by a general strike which took the putschists all means to communicate, even to have light in their buildings, or to move around except in automobiles and per pedes.

Lenin’s August 30/September 12, 1917 letter, which is published in German under the title “Fight Kornilov in order to overthrow Kerensky” https://www.marxists.org/archive/lenin/works/1917/aug/30.htm comes to my mind.

The defensive struggle did require to form committees representing the unity in action, and out of those could develop organs of power.

What was possible in the concrete German situation after the defeat of the Kapp Putsch – I don’t know. My knowledge is too thin in that respect. I have here a 1000-page book by a Erhard Lucas “Märzrevolution 1920”, but I have never read it. Any way, the revolutionary wing of the workers movement would have to fight for a united front, but not by waiting until the most rightward reformist leaders would have agreed to form a united front, but going ahead with mass actions, and draw as much people as possible into it, including the leaders of other parties and tendencies in the workers movement.

I know that in the end, the March uprising had been defeated — well, the 1848 revolution was defeated, too, as was the Paris Commune and the 1905 revolution in Russia, the other revolutionary upheaval

We can’t change history, but we can learn from it.

In the Weimar republic, defense of democracy was made very concrete by the Kapp Putsch in 1920. Should workers ally with the Weimar constitutional government against the coup? After some wavering, Communists of the time concluded “yes.” Should they have fought for a workers’ government to initiate a transition beyond that constitution? There was a great debate on that point, which still continues.

Frederick Engels argued in his 1865 article on “The Prussian Military Question and the German Workers’ Party” against the politics of the Lassallean party, without naming it, to look positively towards and alliance with Bismarck and the feudal landed aristocracy against the industrial bourgeoisie “for universal suffrage”, and stressed that the working class should rather fight for the freedom of the press, freedom of assembly and freedom of association, as the material guarantees for the freedom of movement of the working class movement.

“Now even in France [under the rule of Napoleon III], where after all virtually all the peasants are free and own their land and where the feudal aristocracy has long been deprived of all political power, universal suffrage has not put workers into the Chamber but has almost totally excluded them from it. What would be the consequence of universal suffrage in Germany, where the feudal aristocracy is still a real social and political power and where there are two agricultural day labourers for every industrial worker? The battle against feudal and bureaucratic reaction — for the two are inseparable in our country — is in Germany identical with the struggle for the intellectual and political emancipation of the rural proletariat — and until such time as the rural proletariat is also swept along into the movement, the urban proletariat cannot and will not achieve anything at all in Germany and universal direct suffrage will not be a weapon for the proletariat but a snare.”

Engel’s article is available in the “Marxists Internet Archive” (MIA)
at https://www.marxists.org/archive/marx/works/1865/02/12.htm
Worth reading, especially part III which deals with the above mentioned political questions.

Shortly after the publication of Engels’ article as a pamphlet, Marx and Engels publicly broke with the Lasallean paper “Sozial-Demokrat” because of the paper’s too cozy relationship with Bismarck.

To summarize: the way is to defend concrete democratic rights like the above mentioned central freedoms of the press, of assembly and association, the right to privacy of mail — physical and electronic — and the home, due process in court, and so on, instead of a vague concept of “democracy” and “freedom of tyranny”. The truth is concrete.