Germans did perceive Jews as dangerous. Jews had a ``Mordplan'' - plans for assassinations of Germans. ``Die Juden sind unser Unglück'', Jews are our calamity, was a motto repeated a countless number of times on newspapers and banners. Following the announcement of a boycott of Jewish stores in 1933, a rally was held in New York's Madison Square Garden. A counter boycott of all German made goods was threatened. On posters attached everywhere on German cities one could read: 
The Jews of the whole world are trying to destroy Germany. German people, defend yourselves! Do not buy  from the Jews! 
But Jews had to be much more dangerous than that: The bogus Protocols of the Elders of Zion unveiled an insinuating attempt to gain control of the whole world. No matter if the Protocols had been exposed as false, they were something  people would believe to. At the same time, literary fiction and movies had since long purported the idea of conspiring, evil Jews:  vile creatures, devoid of real humanity, of roots, that achieved their goals thanks to their mercilessness.