In Dr Carson’s defense, the whole Hitler/Nazi chapter is probably one of the most interesting subjects of recent history. It is the single most studied and well documented event in human history. So many lessons to be learned. People who dismiss it either never heard that old adage about having to repeat it, or are too stupid to appreciate its significance.
Or the people who dismiss it... are in agreement with Statist totalitarianism instead of a Constitutional Republic and the Bill of Rights including the 2nd Amendment.