Answer:
It was because of antisemitic ideas.
Step-by-step explanation:
During the First World War (1914-1918), Hitler was a soldier in the German army. At the end of the war he, and many other German soldiers like him, could not get over the defeat of the German Empire. The German army command spread the myth that the army had not lost the war on the battlefield, but because they had been betrayed. By a ‘stab in the back’, as it was called at the time. Hitler bought into the myth: Jews and communists had betrayed the country and brought a left-wing government to power that had wanted to throw in the towel.
By blaming the Jews for the defeat, Hitler created a stereotypical enemy. In the 1920s and early 1930s, the defeated country was still in a major economic crisis. According to the Nazis, expelling the Jews was the solution to the problems in Germany.