I think there is an unfortunate habit here, as well as in general, to assume that racism, and specifically Nazi racism, was a coherent ideology based on an unchanging set of principles. I see a lot of questions about the Nazi stance on (insert race/nation) or how the Nazis reconciled their beliefs with (insert uncomfortable fact). Nazi ideology, like most race-based beliefs, was essentially self-serving. There is a bit in Speer's autobiography where Hitler says in response to Owens that blacks shouldn't be allowed to compete with whites in future Olympic games as they have an unfair biological advantage. He is not depicted as being particularly troubled by this "challenge" to Aryan supremacy. In addition, Hitler long viewed the Slavs as weak, especially in the aftermath of the Soviet war with Finland, but after German setbacks in the East, he had to admit that as a "race" they were in fact very tough and stubborn. There was obviously, however, never any doubt of their essential inferiority. It should also be mentioned that racial strength was not unchanging. The Aryan race was not simply strong by default. It had to be constantly tested and improved through struggle. In fact, the single biggest reversal when it comes to Hitler's views on race would be his views on the German people themselves. Towards the end of the war, Hitler came to believe that as his people failed to achieve victory, they in fact deserved to be destroyed as in the great struggle of races they ended up on the losing side.