When Adolf Hitler was a frequent out-of-work artist in Bavaria, a lot of extreme right wing politicians and statesmen in those regions (mostly from the lower middle class) held the view that in World War I, Germany had been "stabbed in the back" by socialists, communists, Bolsheviks, intellectuals and Jews. Culturally, the legendary dagger-stabbing of the German Army parallels Siegfried's fate in the epic poem Song of the Nibelungs, wherein Siegfried - the heroic pinnacle of German culture - is stabbed in the back by Hagen von Tronje when the latter finds out about the warrior's weak spot on his back.
The Dolchstosslegende ("stab-in-the-back legend) popped up because most Germans at that time thought that the "unpatriotic acts" of Social Democrats (of which there were many in the Reichstag) and Jews (of which there were many in Germany, and held or worked in businesses that were considered crucial to the World War I cause - such as weapons manufacturing) contributed to Germany's loss.
Contributing to the Dolchstosslegende were -
1) Strikes in the German arms industry at a critical moment of the offensive, leaving soldiers without an adequate supply of materiel. Most of these strikes were allegedly concocted by people allied with Social Democrats and Jews.
2) Kurt Eisner's (a Berlin-born Jew) essays on the illegality of Germany joining World War I; he also had a hand in concocting the aforementioned war materiel manufacturing strikes
3) The temporary German "civilian government" immediately sued for peace once Kaiser Wilhelm II abdicated and the military government dissolved. The signature on the document for the armistice was Matthias Erzberger, an anti-war advocate (and a Jew). This led to the signing of the Treaty of Versailles, in which Germany was forced to accept a War Guilt Clause - meaning, Germany had to accept complete responsibility for the hostilities and put up war reparations that practically exhausted a lot of financial resources.
Now, imagine a humiliated Germany, with hyper-inflation and rapidly escalating unemployment after the Treaty of Versailles, a weak Weimar Republic, an embattled deutschmark, reduced territory and cost of living that would hardly feed a family of four (much less a single German). This is the stage set for Adolf Hitler (who absorbed all the prejudices of the lower middle class of Bavaria and Munich) and carried that Dolchstosslegende notion with a blueprint for revenge, expansion and conquest that was to be fearsomely carried out. Many a German citizen had no money and no job at that time, and when a leader assumed power and that showed that you can have a job, you can keep that job, and you can have money to stash away, I guess most Germans had to go with the flow. After all, those were times that Germans felt that they had their backs to the wall.
Personally I don't agree with his methods, most especially his battlefield logic. But to turn around a nation shod with economic conditions no one would wish upon another in a short span, that is something.