throughout the weimar era, the kpd viewed the social democratic party of germany (spd) as its main adversary, and the kpd referred to the spd as "social fascists." the kpd regarded itself as "the only anti-fascist party" in germany and held that all other parties in the weimar republic were "fascist". nevertheless it cooperated with the nazis in the early 1930s in attacking the social democrats, and both sought to destroy the liberal democracy of the weimar republic. in the early 1930s the kpd sought to appeal to nazi voters with nationalist slogans and in 1931 the kpd had united with the nazis, whom they then referred to as "working people's comrades," in an unsuccessful attempt to bring down the social democrat state government of prussia by means of a plebiscite. 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.