The main thing is Hitler was interested and towards the majority and they are Aryan Germans.
Whereas Jews in Germany were in less number(2.5%)
and he took it as advantage and want to desert and kill the Jews there,And he also  said that the main cause of the problems in Germany were the Jews and he put them in Concentrated Camps and arrested them without no reason(Arbitrary) and punished them severely and killed them.
this was the Main reason for what Hitler TARGETTED Jews as their enimies.