Hitler picked up his anti-Jewishness in the 1920's in Munich. His local socialist group was opposed by the local Jewish-promoted communist group. The newspapers would routinely print misleading information about the times and dates of his group's rallies to disrupt attendance, or simply "forget" to print his ads. They would low-ball attendance figures, make false accusations, etc. Sound familiar? Anyways, he discovered all the media was Jewish-owned and that he was being unfairly treated.