WHY IS "NAZI" A BAD WORD BUT NOT "COMMUNIST"?

Dennis Prager asks a good question:

Given the amount the human suffering Communists have caused - 70 million killed in China, 20-30 million in the former Soviet Union, and almost one-third of all Cambodians; the decimation of Tibetan and Chinese culture; totalitarian enslavement of North Koreans, Chinese, Vietnamese, and Russians; a generation deprived of human rights in Cuba; and much more — why is "Communist" so much less a term of revulsion than "Nazi?"

Further, why are Christians supposed to be so evil because of the Inquisition etc, when, as is pointed out in Dinesh D'Souza's excellent book, What's so Great About Christianity, the atheism of Communism killed more than 10 times as many people despite its being in existence for a mere hundred years or so?

Check his answer in the Jewish World Review.