The Nazis fought the German Communists for control of Germany, not unlike a “turf war” between two street gangs.
From April 1924 until late February 1925 the SA was known as the Frontbann to try to circumvent Bavaria's ban on the Nazi Party and its organs (instituted after the abortive Beer Hall putsch of November 1923). The SA carried out numerous acts of violence against competing socialist groups throughout the 1920s, typically in minor street-fights called Zusammenstöße ('collisions'). As the Nazis evolved from an extremist political party to the unquestioned leaders of the government, the SA was no longer needed for its original purpose: the acquisition of political power. An organization that could inflict more subtle terror and obedience was needed, and the SA (which had been born out of street violence and beer hall brawls) was simply not capable of doing so. The SA also posed a threat to the Nazi leadership and to Hitler's goal of co-opting the Reichswehr to his ends, as Röhm's ideal was to incorporate the "antiquated" German army into a new "people's army": the SA. The younger SS was more suited to this task and began to take over the previously held roles of the SA.