IE just ate my first answer (I want Ajax- or something to that effect, saving my drafts), and maybe that was good , but this second reply might be even more disjointed.

another problem I have with the comparison argument is: Nazism is seen as the utter evil incarnate. But if 25% of Germans to date (and an even higher percentage of over 50%) say there were good things done under the Nazis, then that also means, that as a warning, it will come as bad as it was under the Nazis, has only limited effect. those 25% will think, but heh, wasn't that bad, my family survived, thrived, made millions (yes, I am looking at George W. Bush and his Grandfather) - so why is he making such a fuzz?

If you want to connect with right wingers and tell them what bad will happen, when they support the limitations of freedom and compare it to the Nazi's, they will say, but the Nazi's had a clear politic on racial purity, that I would love to have, what are you trying to make me afraid off?
However, if the Nazi comparison is not triggered, that person might come around to the realisation of the consequences of limitations of liberties and will support your point of view.