Full Idea
A standard problem for existentialism is the 'sincere Nazi'; there were undoubtedly some true believers, who saw in Nazism a creed that they wanted to believe, and who freely chose to endorse it.
Gist of Idea
A standard problem for existentialism is the 'sincere Nazi'
Source
Gordon Graham (Eight Theories of Ethics [2004], Ch.5)
Book Reference
Graham,Gordon: 'Eight Theories of Ethics' [Routledge 2004], p.86
A Reaction
The failing of Nazis was that they were not good citizens. They might have been good members of a faction, but they were (in my opinion) poor citizens of Germany, and (obviously) appalling citizens of Europe. The objection to existentialism is good.