Check out this book. Written by a Jewish man, former head of the ACLU.
https://www.amazon.com/Defending-My-Enemy-American-Freedom/dp/1617700452
That seems to be quoted around these conversations often as a "them's the facts" trump card, and I'm pretty sure that many who post it don't seem to grasp the meaning.
Here's an interesting read for you by Aryeh Neier, one of the founders of the Human Rights Watch group and a holocaust survivor as well.