People with knowledge of this subject find they have to ********* around.
Hitler fought alongside Jews in WW1 - he had no particular problem with them. In 1918/19 he was confronted with the Bolshevik attempt to take power by revolutionary violence in Germany. The Spartakists, led by 2 Jewish Bolsheviks. The moneyed Jews were against the Bolsheviks, because they were class enemies - but these intricacies were lost on the common populace: you know how these things play out even nowadays.
Then he will have looked into it a bit more, aided by anti-Semitic reactionary extremist propaganda. In the mid-19th century the cloth factories in the Russian Empire overwhelmingly employed poor Jews - who then formed a huge trade union, which was active in labour relations and the Jewish Emancipation movement. This trade union much later merged with what became the Communist Party. Think about it: the CP had about 30,000 members the trade union about 300,000. Guess what? The Russian Communist Party was overwhelmed by Jewish socialists, and in the normal way of things they self-perpetuated by promoting people they knew and trusted. In fact, as things stood in 1919-21 - the key years in Hitler's political 'coming of age' it would have been perverse for the over-generalising people of the time to view the Bolshevik coup d'etat as anything but a takeover of Russia by Jews and mixed-Jews. The overwhelming majority of leading Communists were Jews and mixed-Jews - this did not change in any real sense until Stalin's purges, when the Jewish element was much diminished.
Add this to the many high-profile socialists with Jewish origins (esp. Rosa Luxemburg and Karl Liebknecht) and BANG! you get full-blown Nazism devoted ostensibly to nationalist flavour socialism (i.e. strongly German and anti-toff). Of course, they sold out to big business because they needed all the help they could get, e.g. Krupp arms manufacturers.
Much else could be added, but they would be details. Hitler's anti-Semitism is perfectly understandable when viewed in the perspective of the time. Still vile, mind.