Historian Rick Perlstein has made a career of translating the American right for the liberal left. His book-length works have identified one Republican after another — first Barry Goldwater, then Richard Nixon, now Ronald Reagan — as prisms through which we can understand the modern GOP. While his books lack the rigor of principally archive-based scholarly work, all three are breezy, fun reads that capture the mood of their respective eras, especially when it comes to the oft-forgotten zaniness of conservatism in the 1950s, ’60s, and ’70s.

But according to Perlstein’s new piece in the New York Times Magazine, the election of Donald Trump has caused him to reconsider everything he thought he knew about the American right and the appeal of its ideas to average voters. Perlstein thinks other historians need to do the same.

“We advanced a narrative of the American right that was far too constricted to anticipate the rise of a man like Trump,” Perlstein claims. To understand Trump, Perlstein continues, one needs to reach back beyond Reagan or Nixon or Goldwater to the “reactionary traditions” of the 1920s and ‘30s, including the Ku Klux Klan, businessman Henry Ford, and radio priest Charles Coughlin.