Originally published by The Free Press. As the algorithmic age takes Holocaust denial mainstream, historians must admit a bitter defeat. When the two of us met at Harvard 15 years ago, one was a professor teaching modern history, and the other was an undergraduate interested in the future of artificial intelligence. The elder of us had published a succession of books concerned with one of the most important and intractable questions of the 19th and 20th centuries: Why did the successful economic and social integration of the Jews after their emancipation or westward emigration produce such a vitriolic backlash? A...