Q: Why is it that it's okay to say that something had its origin with "Commie Jews" but it's not okay to say that the Nazi Party had its origin with "Facist Christians"?
A: Intellectual dishonesty.
The argument that you would present is that once the Christians became Nazis they ceased to be Christians in some sort of act of magic.
What is your central point? Should we do anything to alleviate the problem? If so, what?
His comment about commie Jews was stupid and anti-Semitic, but I'd like to point out that a Christian who becomes a Nazi is indeed no longer a Christian, for the same reason a Christian who becomes a Muslim or an atheist is no longer a Christian. There a some views that are simply inconsistent with Christianity.