After the Nazi electoral breakthrough in the 1930 Reichstag election, the SPD proposed a renewed united front with the KPD against fascism but this was rejected.[25]
In the early 1930s, the KPD cooperated with the Nazis in attacking the social democrats, and both sought to destroy the liberal democracy of the Weimar Republic.[26] They also followed an increasingly nationalist course, trying to appeal to nationalist-leaning workers.[4][27]
In 1931, the party reported a membership of 200,000.[28]
The KPD leadership initially first criticised but then supported the 1931 Prussian Landtag referendum, an unsuccessful attempt launched by the far-right Stahlhelm to bring down the social democrat state government of Prussia by means of a plebiscite; the KPD referred to the SA as "working people's comrades" during this campaign.[29]
In this period, while also opposed to the Nazis, the KPD regarded the Nazi Party as a less sophisticated and thus less dangerous fascist party than the SPD, and KPD leader Ernst Thälmann declared that "some Nazi trees must not be allowed to overshadow a forest [of social democrats]".[30] In February 1932, Thälmann argued that “Hitler must come to power first, then the requirements for a revolutionary crisis [will] arrive more quickly”. In November 1932, the KPD and the Nazis worked together in the Berlin transport workers’ strike.