The Night of the Long Knives, in June 1934, saw the wiping out of the SA's leadership and others who had angered Hitler in the recent past in Nazi Germany. Fearing that the paramilitary SA had become too powerful, Hitler ordered his elite SS guards to murder the organisation’s leaders, including Ernst Röhm. Also killed that night were hundreds of other perceived opponents of Hitler, including Kurt von Schleicher and Gregor Strasser. After this date, the SS lead by Heinrich Himmler was to become far more powerful in Nazi Germany.
For all the power the Enabling Act gave Hitler, he still felt threatened by some in the Nazi Party. He was also worried that the regular army had not given an oath of allegiance.By the summer of 1934, the SA's numbers had swollen to 2 million men. They were under the control of Ernst Röhm, a loyal follower of Hitler since the early days of the Nazi Party. The SA had given the Nazi's an iron fist with which to disrupt other political parties meetings before January 1933. The SA was also used to enforce law after Hitler became Chancellor in January 1933. To all intents, they were the enforcers of the Nazi Party and there is no evidence that Röhm was ever planning anything against Hitler.
However, Röhm had made enemies within the Nazi Party - Himmler, Goering and Goebbels were angered by the power he had gained and convinced Hitler that this was a threat to his position.