We owe largely to Ernst Zündel the establishment of the strong foundation on which Holocaust Revisionism today stands, since it was he who organized Revisionist scholars and commissioned further research for his defense in the famous series of "False News Trials" in 1985, 1988, and 1992. The Leuchter Report was commissioned for the 1988 trial, where celebrity historian David Irving also testified, himself having been convinced by the Leuchter Report.
The reverberations from Zündel's defense at those False News Trials have not ceased. Not long after the 1988 trial, Professor Yehuda Bauer of the Yad Vashem Holocaust Museum declared that the death-tolls for Auschwitz must be reduced, because they were too high to be credible, and the "neo-nazi deniers of the Holocaust," he said, would call attention to this. So the death-toll for Auschwitz was drastically reduced in 1990. That solved one problem, but it created other, new problems. The official reduction of the death-toll for Auschwitz means that the confession of one of the commandants of Auschwitz, Rudolf Hoess, was false. This, in turn, means that all such confessions are dubious. After the damage inflicted by Ernst Zündel, the Holocaust has become like a knitted garment unraveling.
Suppression of reporting about Holocaust Revisionism has slowed that process in Europe and the anglophone world, but in the long term there will surely be nothing left of the Holocaust -- nothing qualifying it for the enormous attention that it has received -- and it was Ernst Zündel who initated this process.