If you want evidence that Holocaust denial remains an active problem, says historian Deborah E. Lipstadt, just check out the YouTube comments on the trailers for the new movie Denial or the Amazon reviews of her book History on Trial, on which it's based.
"Of course the thumbs down and the comments on [the trailer] were pure anti-Semitism," Lipstadt tells TIME.
The movie and book, which was recently re-released with the same title as the film, tell the true story of what happened following the publication of Lipstadt's 1993 book Denying the Holocaust. David Irving, one of the people called out in her book, sued her in the U.K. for libel. She and her legal team—due to the burden of proof in the British law system—ended up having to essentially prove in court that the Holocaust happened, in order to show that the statements in her book were true and thus not defamatory, and that Irving's interpretations were skewed. (They did so successfully.) Lipstadt says that when she first looked into the history of Holocaust denial, she expected it to be a brief tangent to the rest of her academic career. Decades later, it has become the work for which she's best known.
The road from the 1940s to the days of YouTube comments has been long. While Holocaust denial—the lie that all or part of the Holocaust is a hoax—has been a phenomenon since World War II ended, Lipstadt says, the forms it has taken have changed a lot.
"In the mid-’70s the deniers changed their M.O. and they did something, which is not uncommon among conspiracy theorists today and among extremist groups today, where they still held the same beliefs as before, but their outer presentation became much more academic-like," she explains. "They began to publish books with footnotes. They began to hold conferences. They began to show up on television where they were often given a voice. But instead of looking like neo-Nazis, dressed in stormtrooper uniforms, they began to talk in a very measured way about how the documents showed that [the Holocaust] was impossible."
Lipstadt attributes part of the shift toward academia to the rise of deconstructionism—which she calls the idea "that you can look at a document and interpret it in any way you wish." Though the school of thought has many aspects to recommend it, she says, it made academics more open to the idea that anything could be seen from two sides. In that environment, Holocaust deniers—or at least the brand of them that features in Denial—were able to make new inroads in portraying that denial as a legitimate opinion.
"[But] if I said to you that I believe that the Earth is flat or I believe the Civil War never happened, I could say 'that’s my opinion' and you would end the conversation very quickly," Lipstadt explains. "That’s not opinion, that’s a lie."
Then, when the early Internet came around in the decades following that shift, she says, its echo chamber effect enabled those who were convinced by the deniers to find a community of others who cited the same sources. And, she says, Holocaust deniers are not the only conspiracy theorists for whom that situation holds true.
"I think we’re living at a time when conspiracy theorists and people with outlandish ideas that do not correspond to the facts are finding more of a fertile field, more of a welcome, more of an ability to promulgate their claims than we’ve ever had before," she says. "If some people take away from this movie the notion that there’s a difference between facts, opinions and lies, I will be very satisfied."