Why does he refer to Hitler’s Nazi Germany? What point is he trying to make?

“We should never forget that everything Adolf Hitler did in Germany was "legal" and everything the Hungarian freedom fighters did in Hungary was "illegal." It was "illegal" to aid and comfort a Jew in Hitler's Germany. Even so, I am sure that, had I lived in Germany at the time, I would have aided and comforted my Jewish brothers. If today I lived in a Communist country where certain principles dear to the Christian faith are suppressed, I would openly advocate disobeying that country's antireligious laws.”

Here, Dr. King describes what happens when one relies on a law that exempts itself from moral responsibility. On several occasions in the “Letter,” he chides the clergy for representing a church that is separate from social, ‘real-world’ concerns. His argument here is that allowing a law to reign supreme without assessing its moral quality produces a situation like that of Nazi Germany. His attack here on the clergy – who seem to support ‘law and order’ without considering the repressive segregation that comes with such order – is not very subtle, comparing them to Nazis who persecuted Jews simply because their prejudices were protected by the law. What the passage does is distinguish between conformity and individual responsibility. The latter, he argues, allows for action that can change the world. By suggesting that he would have broken Nazi laws because they were unjust, he challenges his audience to do the same with segregation laws.