Alan Lichtman made his first presidential prediction in 1984 and has gotten them all right ever since. He credits this prophetic success to a scientific model which never fails. And this model indicates that come January, Donald Trump will be moving to the White House.

But now, for the first time since he took on his presidential prediction mission, the Jewish history professor from American University in Washington is adding a measure of caution to his forecast. Not because the idea of his prediction coming true is too “frightening,” as Lichtman put it, but because Donald Trump is such an unusual candidate, he may defy even the most scientific of prediction models.

“For the first time in 30 years, I qualified my prediction,” Lichtman said in an October 6 interview, “because Donald Trump could be a history shattering candidate.” Lichtman noted that the Republican candidate’s lack of political experience and the “scandals that keep piling up” as the campaign moves forward, “suggest that if any candidate can break the historic force, it’s Donald Trump.”

Lichtman’s prediction, which gives Trump the victory, stands in contrast to most other presidential election forecast models which view Hillary Clinton as the likelier candidate to win on November 8. But Lichtman looks at elections differently. Instead of averaging polls, he bases prediction on a “13 key system” he developed with Russian mathematician Vladimir Keilis-Borok. It asks 13 questions focused on the political landscape, state of the economy and of foreign relations and the candidate’s charisma. The keys are designed in a true/false formula and if six keys show “false,” the challenger party, currently not in power, will win the White House. This year, there are exactly six such flags, meaning Republicans are poised to win.

“I’d love to say that I spent years in research on this model,” Lichtman said, “but the truth is I developed it by accident.” A conversation with Keilis-Borok in California Institute of Technology in 1981 and began to discuss a possible collaboration. The result of their joint work was a predictor very different than any other model aimed at forecasting election results. It weights all “keys” equally, eliminating any variable factors that other models are based on, and focuses on the performance of the party in power as the way of understanding whether voters will want to give it another chance to occupy the White House.

“It suggests why these elections are so close,” he said, explaining that while Clinton was wondering why she’s not leading by 10%, the truth is that she is up against a historic trend that has made these elections so close.

After several years of successfully predicting the presidential election outcome weeks before Americans went to the polls, Lichtman began to gain a guru status, attracting national media’s attention to the history professor who figured out a fool proof system. Standing out this election cycle as the only reputable expert betting, though in a conditioned manner, on a Trump win, brought Lichtman even more publicity and he has been constantly courted by reporters.

Born in Brooklyn, New York, in 1947, Lichtman was educated at Brandeis University and Harvard and has spent most of his academic career at American University where he is now a distinguished professor of history. Political predictions are only a small part of his academic work, which focuses on American political history.

Lichtman’s success in predicting presidential elections did him no service in the one time he himself tried to enter politics. In 2006 Lichtman ran for the U.S. Senate in the Maryland Democratic primary, on a progressive platform based on his opposition to the Iraq war and his call to end the use of fossil fuels. Lichtman gained just over 1% of the votes in a race that was won by Ben Cardin, who went on to win the Senate seat.

One of Lichtman’s well known academic works is the book “FDR & the Jews” he co-authored with Richard Breitman, which offered a complex approach to the former president’s relationship with the Jewish community.

It is Lichtman’s Jewish background and values that now make him so concerned about the prospect of his own prediction coming true. “As a Jew, Donald Trump frightens me,” he said, listing incidents in which the Trump campaign has dabbled racial and bigoted rhetoric and associated with white supremacist activists. “He has aroused some of the anti-Semitic voices in this country and I find that extremely troublesome.“

Contact Nathan Guttman at guttman@forward.com or on Twitter @nathanguttman