I am not saying that gas chambers did not exist. I did not see them myself. I haven't studied the questions specially. But I believe it is a minor point in the history of the Second World War.
Source, in full
Controversial statement on the Holocaust (13 September 1987), in which he referred to the Nazi gas chambers as a "minor point" [point de detail] in the history of the Second World War, as quoted in Annals of the American Academy of Political and Social Science (1993)