Jill Lepore is the David Woods Kemper ’41 Professor of American History at Harvard, and also a staff writer for The New Yorker. Her new book is These Truths: A History of the United States. This interview has been edited and condensed.

Listen to Jill Lepore on the Start Making Sense podcast.

Jon Wiener: Your new 900-page history of America ends with Donald Trump. This is not a happy ending. When you were writing this book, where did you think the story would end?

Jill Lepore: When I set about to write the book, which was a few years ago, I initially thought I’d end it in January 2009, with the inauguration of Barack Obama. It’s a great ending: It’s very cinematic. It has all kinds of drama to it. And it hits a lot of themes in American history: the struggle over equality and the long fight for racial justice in the United States. It’s a moment of political celebration. And it is also comfortably in the past. Historians don’t generally like to write about the present or the near present because we have insufficient vantage on it. But I was about halfway through writing the book, writing about the Civil War era, when Donald Trump defeated Hillary Clinton. I realized immediately that I would need to adjust my ending. It seemed like a dereliction of duty as an intellectual not to attempt to wrestle with the election of Donald Trump.

JW: The history that ends with the election of our first black president is very different from the history that ends with Donald Trump—or is it? Did you revise what you had planned for the lead-up to Obama? Did you take out some Martin Luther King and add more George Wallace after Trump got elected?

JL: No, I didn’t. The book reads a little bit differently now with Trump in the White House than it would have otherwise. Maybe the words of George Wallace leap out on the page, and the words of Martin Luther King maybe don’t so much, or maybe King’s words don’t seem to operate as, say, foreshadowing, while Wallace’s do. Both of those men said what they said, no matter what happened next. And remember that it was a close election and that Donald Trump didn’t win the popular vote. It certainly could’ve gone another way. So it doesn’t actually represent the upending that the panic about the election elicited. Of course, it is a completely different political direction for the country. But the same country, with the same history, elected both Obama and Trump.

JW: American historians now are supposed to be able to answer the question, “How bad is Donald Trump, compared to all the rest?” Is he really the worst? How badly have presidents behaved in the past? This is a question that you’ve looked into.

JL: Long after I finished writing this book, I was fascinated to discover that the Watergate committee in 1974 had invited the great Yale historian C. Vann Woodward to compile a report that tried to answer the question with proper historical method, “Has any president done the kinds of things that Nixon stands accused of having done?” (I wrote a short piece about this for The New Yorker last month.) They wanted that report because there were plenty of Republicans on the Senate Judiciary committee, the committee that was conducting the Watergate inquiry, who kept saying, “Every president did this kind of stuff. This is just politics as usual.” So Woodward got together some colleagues, and they got together some of their graduate students, and in a whirlwind summer, they compiled a report on every single American president, a report that is basically a litany of presidential misdeeds and how they were handled. But by the time they submitted their report, Nixon had all but resigned. So the report had no impact whatsoever on the proceedings, and it disappeared. Woodward had it printed, but the book very quickly went out of print. Still, it’s fascinating reading. Woodward, summing up, concluded that there had been a lot of misdeeds, a lot of corruption, a lot of chicanery, a lot of graft, a lot of lying. But, he concluded, the specific kinds of constitutional violations that Nixon had committed were unprecedented—in lots of ways.

I tracked down the historians who had worked on that project who were still alive. I asked them to compare what they had learned about the previous presidential administrations and the low-water mark that Nixon represented, and asked them the question, “Has any president been as bad as Trump?” They had strong words about the unprecedented nature of what Trump has done. They focused not just on what Trump stands accused of—the allegations of collusion with the Russians, for instance—but also on Trump’s public defilement of democratic institutions and foundational American values. They focused less on constitutional violations and more on Trump’s debasement of our democracy. William Leuchtenberg, now 95, told me about Nixon that “what he did does not match the Trump presidency in its malfeasance, and in the depth of his failure as president.”

JW: I wanted to ask about Andrew Sullivan’s review of your book in The New York Times. He said he concluded from your book that “the Civil War would never end.… And its toll on the human spirit and the black body was matched only by its evil. From Jackson’s massacre of Native Americans to the Southern labor camps to the full embrace of torture in the Bush-Cheney administration is a single, consistent and evil line.” I wonder if you have any comment on that.

JL: As a rule don’t read reviews, and I can’t be accountable for what someone says about my work. But that is a powerful statement, and Sullivan’s a tremendously talented writer. I spend a lot of time in the book talking about how the work of a historian is not the same as the work of a moralist. I think there’s a lot of room for moralism in our political rhetoric, and in political commentary, and I think Sullivan is in many ways in the best tradition of that kind of moralism. That vein of American political journalism is a really important part of how the American republic works and about the check that journalists provide on government. But in writing history I don’t use the language of “evil.” I use the language of tragedy and horror and even of atrocity. And then, when things are beautiful, I use the language of beauty, and grace, and decency.