On that I am in agreement. If they cannot accede to respectful invitations to civil dialogue, then they deserve to be called out.
Interesting that you say that.
You probably wouldn't already know this, but an uncle of mine passed away very recently. He was German born, of a Polish mother and a German Jewish father. During WWII, he fought against the allies. Whilst alive, he seldom spoke of his experiences (he generally seemed far more interested in talking about his subsequent years working as a boiler attendant). He did of course sport a number of injuries to show for his time in battle (missing fingers and bullet wound scars etc.). Needless to say his father (my grandfather), did not survive those horrendous times.
Anyway, I digress.
What I really feel the need to mention, is that, invalid comparisons to Nazism, have become so commonplace now, that its meaningfulness has diminished. Such comparisons, though they may in some cases be meritorious, tend to stifle, rather than progress, the discussion, whilst at the same time doing an injustice to those afflicted by the atrocities perpetrated during those times.
Having said that, it doesn't mean that the underlying characteristics of any philosophical ideology (whether it be Marxism, Nazism, or any other ism for that matter) needn't be analysed for comparative purposes.