How did Nazi ideology lead to the extermination of millions of innocent people during the Holocaust?

Hitler and the Nazis believed that it was the Jews fault they lost WW1 some that were the holocaust comes in he wanted to kill all the Jews. He wanted to kill black people because he believed white is the was the only race the world should have. He killed Soviet POWs because Hitler hated communist. He killed Handcappied people because the were "incurably sick". He killed Ethics Poles and many other people.