It has been a common tactic among creationists to attempt to discredit scientific ideas by linking them to the horrific actions of the likes of Hitler and the Nazis. The scientific merits of a theory do not rest on its societal implications, of course, but there is also the issue that the Nazis did not take any of their ideas from Darwin or evolutionary concepts. Rather, as this very thorough debunking by UK astrophysicist Coel Hellier shows, it was quite the opposite in that the Nazis had an explicitly creationist ideology.
Nazi racial ideology was religious, creationist, and opposed to Darwinism
Thorough takedown of the supposed connection between Darwin and Nazism. is a post from Genomicron.