As real-life victims and eye-witnesses die off...
This is what history fears the most, coming to past. As real-life victims and eyewitnesses to the Holocaust die off, it becomes easier for Holocaust deniers.
If the Holocaust never happened then the late President Dwight Eisenhower and the late Lieutenant General George Patton were liars. Both men visited the concentration camps and recounted the horror they witnessed in their memoirs. One of my relatives toured a concentration camp in Germany many, many years ago and personally saw the ovens. The Nazi German monsters didn't build those concentration camps for looks. Those were built for one and one purpose only, the slow or quick execution of persecuted human beings.
All those horrifying black and white films showing dead skeletal bodies of starved and gassed humans dumped into mass graves cannot be denied and yet the deniers claim those films are fabrications. Those must be a lot of expensive props of dead bodies. Others claim the films were of Russian gulags or prisoner of war camps.
There was a colleague of mine who told me that he quietly ended his friendship with a nice Middle Eastern guy because the man adamantly denied the Holocaust ever took place. He claimed it was all a worldwide Jewish conspiracy and that the names of the victims were dredged up from innumerable telephone books at random. Six million Jews and six million political prisoners, gypsies, homosexuals, mental deficient people, physically deficient folks...all don't simply vanish off the face of the earth without someone noticing.
Remember the kids' movie from 1972, WILLY WONKA AND THE CHOCOLATE FACTORY? Being filmed in Europe, the producers and director needed to find small people, aka midgets and dwarves for the roles of the Oompa Loompa people. But they couldn't find enough in Germany. Adolf Hitler and the Nazis had done a thorough job of ridding Germany of imperfect, undesirables.