Trump Isn’t Hitler. But the Lying … - The New York Times

It is a commonly accepted rule among those who are in the business of argument, especially online, that he or she who invokes Adolf Hitler, either in oratory or essays, automatically forfeits the argument. The reference is deemed far too extreme, too explosive, too far beyond rational correlation. No matter how bad a present-day politician, not one of them has charted or is charting a course to exterminate millions of innocent people as an act of ethnic cleansing. Hitler stands alone in this regard, without rival, a warning to the world about how evil and lethal human beings can be, a warning that what he did can never be allowed again.....
https://www.nytimes.com/2017/10/19/opinion/trump-isnt-hitler-but-the-lying.html?em_pos=small&emc=edit_ty_20171019&nl=opinion-today&nl_art=1&nlid=78638145&ref=headline&te=1&_r=1