What was Hitler's problem with Jews?
Hitler grew up in a time when Antisemitism was rampant throughout Europe. To make matters worse, it appears his father was particularly virulent in his personal Antisemitism. As often happens with people who are Supremacists, Hitler blamed his own failings on a convenient minority group, in his case the Jewish people. When he entered into politics, he found that many people shared his Antisemitism; so Hitler could use the Jewish people as political scapegoats for the ills of post-WWI German society.