Anti-Semitism existed since the crucifixion, but the biggest single impetus on the Nazi movement in Germany belongs to the teachings of Martin Luther.
Jews were already despised in Germany before Hitler. The Great Depression, in conjunction with the advent of Hitler, propelled it into the forefront.
While another poster called me historically ignorant, I am fairly certain that Luther predated The Protocols of Zion.
Nazi antisemitism had nothing to do with Christianity which Hitler rejected as a weak Jewish slave religion. Hitler's antisemitism was based on the theory that a Jewish-Masonic conspiracy was out to get Germany. He got that straight out of the Protocols. Nothing to do with the crucifixion of Jesus at all. Christianity was believed to be part of the conspiracy to make Germans weak and make them worship a Jewish God.
The RCC cult practiced anti-Semitism long before Martin Luther.
http://www.religioustolerance.org/vat_hol11.htm