If you had to choose the three biggest scoops of the 2016 campaign, what would they be? The New York Times’ reporting on Donald Trump’s taxes would surely make the list. So would the Washington Post’s coverage of the Trump Foundation’s shady endeavors. And then, of course, there was the Post’s revelation, last week, of the Access Hollywood tape in which the Republican candidate bragged about sexual assault. Two of these scoops have been the work of one reporter.

David Fahrenthold joined the Post fresh out of college in 2000. After covering everything from the local D.C. metro area to Capitol Hill, he transitioned to the campaign trail in 2015. As a result of his indefatigable reporting, he has owned the Trump Foundation beat since he started writing about it in January. I spoke by phone with Fahrenthold this week. During the course of our conversation, which has been edited and condensed for clarity, we discussed his experiences reporting on Trump, the Washington Post’s evolving newsroom, and why the Access Hollywood tape might have been leaked to him.

Isaac Chotiner: How did you find yourself on the Trump charity story?

David Fahrenthold: It started back in January. He skips the Fox News debate and holds a veterans’ fundraiser. He says he raises $6 million, including $1 million from himself. But you could tell he had not given away all the money that he said he’d raised. So I came back and said I would check. Maybe there was a simple answer to it. But then it wasn’t that simple. And that set me on a path, first with the veterans’ money, and then once that was settled, seeing whether he had made good on his other promises to give to charity.

When did you sense you had found something juicy?

At first I started doing it in a more traditional way, which is that I would just call the Trump campaign and call the charities that the Trump campaign had identified. So I called them to make sure they got the money, and how much they got, and called the Trump campaign thinking they would cough up the details. They didn’t and didn’t and didn’t. The big change for me was in late May, when Corey Lewandowski called and told me that Trump had given away the million he said he would give, but that it was secret. We couldn’t know who he had given it to.

That seems reasonable.

Yeah, totally. Lewandowski also said people had backed out of the fundraiser but couldn’t say who. The dollar figure was much lower. Then I started trying to figure out whether Trump had actually given the money. I spent a day basically tweeting at veterans’ groups trying to find any evidence that any of them had gotten any of the money. I thought I had just wasted a day tweeting at people and not finding anything. That night, when Trump went on an angry tweetstorm about people questioning him, and the next day when we found out he had really only given the million when I started asking, were signs. The way he treated the money and reacted was a sign that there was a lot more there.

What have your interactions been like with people on the campaign or Trump himself?

I have sent them a lot of questions over email, and in general they don’t respond. Sometimes they do. Lewandowski called, Trump himself called and called me a nasty guy, and then there was a long period of silence.

What did you say when he called you a nasty guy?

Basically I just kept asking him questions. Instead of arguing about whether I was a nasty guy, I would keep asking him questions. He would begin answering a factual question and then it would devolve into name-calling. I am not going to argue about whether I am a nasty guy.

Lately, a couple of times, they have had Boris Epshteyn, who is a Trump adviser, call me. That was a story about how he raises money, where it comes from. Boris told me something that wasn’t true. He gave me an explanation of how Trump raises money, in which he said Trump never takes money owed to him and directs it to the foundation. I immediately said, “are you sure?” And he said, “prove me wrong. That’s for you to find out.” So I offered an example and he said, “prove me wrong again.” They have been weird interactions, and often I am given a story that turns out not to be true later.

How hard was it to learn tax law, or did you already know it?

It was basically zero to 100. I had never covered anything like this, and my knowledge was nil. That’s what’s been interesting about this whole process. There has been stuff I found out months ago but I didn’t know what I had. One example was the $100,000 he paid to settle Mar-a-Lago legal problems. He used foundation money to pay it off. I found out months ago, and didn’t understand until later that he can’t do that. It’s self-dealing. I didn’t know what self-dealing was. I started out thinking I was just looking for evidence of Trump’s giving, but I am now also looking at a story of how he handled money he was given by other people. That I didn’t understand at all.

Who gave you the Access Hollywood tape?

That I can say nothing about.

I thought I might be able to get you if I just slipped the question in.

The Howard Stern model.

Did you get the tape because of your reputation from the foundation stories, do you think?

Well, I can’t say much about it. But I can say that it’s true that I have gotten a bunch of tips from people who would never have known who I was because of the prominence of this. I can’t say what role it played here, but I can say I am getting a lot of tips in general because of that.

They are such different types of stories, with one taking all this effort and study and the other falling into your lap. But maybe it fell into your lap because of all the effort on the foundation story.

It is funny how I have spent this whole year learning the ins and out of New York state tax law, and federal charities law and the story that got the most attention was about something that you didn’t need any legal training to understand. But the tax law stuff, I think, in a way led to this. I think in any story about sex, it’s really hard for tax law to win that battle.

Did your attitude, or the attitude of people in the newsroom, change after Trump went after you guys in June, saying he wouldn’t credential Post reporters to cover his rallies?

The people it really affected were the folks like Jenna Johnson, Jose DelReal, Sean Sullivan, who go out and cover him. You hear from them about waiting in line with the public for hours, and then being told it was full. For them, it was difficult, but I rarely even see them. For the rest of us, the big change was that the field narrowed. That’s what enabled us to focus more on Trump. We had been chasing all these people. Trump is a really complicated story and a difficult candidate to write about. It’s hard to do that when you are covering all these other people.

Under the previous regime, the Washington Post was known for priding itself on being meticulously balanced. When you wrote about government waste in 2014 you were criticized by the left for making it seem like government waste was this super-urgent issue. Now you are going relentlessly after a Republican candidate. Did you change, or have the Post’s ideas about coverage changed, or is Trump sui generis?

I have only ever covered two presidential campaigns, and my role last time around was very different. Every day I was handling the news of the day, and doing rewrites. This time I have been able to focus on reporting more. For me, the thing that is different about Trump is that you don’t realize it, and I didn’t realize it, but there is a rhythm that the political press—including myself—expects people to show in terms of embarrassing statements or shameful acts. And that is: spinning it away and finally being forced to apologize, and then apologize again. There is a ritual and news cycle people expect.

Trump doesn’t really do that or didn’t do that during the primaries. He would say one outrageous thing about Mexicans as rapists or a judge—things that in the past would have set off that cycle. Trump just moved on. The challenge for us was to try to find a way to cover him without relying on that expectation of how he would act, without relying on him to tell us how bad what he did was, or whether something he did was shameful.

Your writing seems to have changed, too. It’s as if you have a longer leash. Does that come from having Marty Baron as the Post’s editor, or is it a change in your thinking?

That’s interesting. To me, the experience that I am trying to draw on are those government-waste stories from 2014 and 2015. They are alike to the charity stories in that they are about obscure things like rules and systems. They are really complicated. In those stories I always tried to make them conversational and use metaphors, and use colorful quotes, to make sure you didn’t lose people as you delved down. I tried to do that on the charity stories. I have been grateful for that freedom to write it.

What’s Marty Baron like as an editor, and how has your relationship with him changed?

I certainly know him better. He’s always been very nice to me but there have always been a lot of layers between him and me, and we have talked in the past but not that often. We have talked much more on this story. There have been questions. Most of my government-waste reporting didn’t rely on anonymous sources or unnamed sources. I have had a few stories here that did.

He was one of the people in the beginning who told me, after the veterans donations, that we should look at the Trump Foundation more generally. That was a good idea. That idea helped guide me for the next few months. I see him more than I used to.

You talk to Bezos at all?

No. I think Bezos may know my name but I have never spoken to him.

Amazon gift cards are in the mail, don’t worry.

Right. I have a little baby at home so we certainly keep Amazon in business.

How are you feeling about the election being over: Thank God, or keep going because you feel like you are onto something?

For a long time, my fear was that I would run out of material to write about before the election was over. I no longer have that. It’s the opposite feeling now. There are some things about Trump’s foundation and charity that I really want to know. I worry there may not be enough time to figure it all out.

Something tells me he is not going to disappear from public life.

That’s probably true. After the election, if he wins it will be really relevant and important and I will probably keep writing about it. If he loses, assuming there isn’t legal fallout with the New York attorney general, and he is no longer a candidate, I really liked those government-waste stories. I’d like to go back to that.

Taxes aren’t sexy enough, so go back to government waste.

That’s the thing about Trump’s foundation: It is easier to cover in some ways because it isn’t shades of gray. It’s not that he gave $50,000 out of his own pocket and I am sitting here saying “as a billionaire he should have given X amount more.” The answers are like, he gave nothing. He gave nothing to his own foundation. He apparently gave nothing between 2008 and this May. That makes it in some ways an easier story to tell because it is so black-and-white.

The proceeds from people clicking on this article will go to my foundation, so thank you.

Fantastic. Make sure you get a good deal on portraits. A lot of people overpay.

Read more Slate coverage of the 2016 campaign.