Donald Trump. MOLLY RILEY/AFP/Getty Images

WaPo's David Fahrenthold is riding the hottest story in politics: The Trump Foundation. David has done massive amounts of reporting that make clear that Trump uses almost none of his own money to make donations from the foundation. I reached out to him to walk through how he happened onto the story, the novel way he has pursued it and what the reaction to the pieces has been. Our conversation, conducted via email and only lightly edited, is below.

FIX: When did you decide to start looking into Trump’s charitable giving through his foundation? Why?

Fahrenthold: The real start of it was the fundraiser that Trump had for veterans in Iowa in late January. He said he'd raised $6 million — and then he toured around Iowa and New Hampshire handing out big novelty checks to local vets groups. But then Trump stopped. And he hadn't given away anywhere near $6 million. That started us looking. We found that Trump seemed to have stockpiled a lot of the vets money in this oddball Trump Foundation, which had no staff and very little money. In fact, for a long time, it seemed the Trump Foundation had actually *made* money on the vets fundraiser, because it had given out far less than it had taken in from other donors (who expected it to quickly pass on their donations to vets groups). 

Washington Post reporter David A. Fahrenthold has been searching for evidence of Republican presidential nominee Donald Trump's charitable giving for months. (Peter Stevenson,Julio Negron/The Washington Post)

The vets saga ended strangely: Trump's people said he'd given the $1 million secretly. We checked. That was false. Trump hadn't given the $1M away at all. Then, he finally did, in the middle of the night. Then Trump held an angry press conference where he denounced the media for, in effect, forcing him to explain what he'd done with the money other people had entrusted to him, the money in the Trump Foundation. That made us more interested. 

Marty Baron, the Post's executive editor,  stopped me in the elevator lobby late one debate night and suggested we look into the Trump Foundation specifically. I also became interested in researching Trump's broader history of charity. If this was how he would act under the microscope of a presidential campaign, how had he acted in past years, back when nobody was looking?

FIX: When did you know you were on to something? As in, when did it become clear that he was giving other people’s money via the foundation rather than donating his own?

Fahrenthold: I started calling charities in June, asking dozens of them if they'd ever received a personal donation, from Trump's own pocket. At that time, I knew Trump had promised he'd given millions of dollars out of his own pocket — but he wouldn't tell us which groups he'd given to, or when. I didn't expect to find all of Trump's giving. But I thought I might find the tip of the iceberg: I'd discover a few large and previously unrevealed gifts from Trump to charities, which would show that he really had been giving his money away in private. After 150 or so, I hadn't found the iceberg. Charity after charity told me they'd never received a cash gift from Trump — or that, if they had, it had been before 2009.

That's when I started to realize that there might not *be* any iceberg. Instead, whenever I found a recent gift from Trump to a charity, it was always the Trump Foundation's money. Which, as you said, was other people's money.

FIX: How helpful are the various charities you have contacted to help you figure out if Trump donated to them personally? What’s the best/worst experience you’ve had in tracking down a Trump donation (or lack thereof)? 

Fahrenthold: I've actually been very pleasantly surprised. Out of the 327 charities that I've contacted, 199 have given me some kind of answer: They said Trump never gave, or that he'd given in the past but not recently, or that their records weren't in good enough shape to be sure. Another 86 have no-commented, which is just fine, too. Only 40 have been unresponsive. The one pattern I've noticed is that, in general, the worst charities to deal with are the ones that are named after athletes. The non-responses include charities named for golfer Annika Sorenstam, baseball players Derek Jeter and Darryl Strawberry and football player Rodney Peete. For some reason, those are the black holes. I must have tried Derek Jeter and Annika Sorenstam's groups 10 times each. Nothing.

I've had a lot of really good experiences with charities, though. I've got to give special praise for Matt Ladika, at a Florida charity called HomeSafe. They were the ones that got this now-famous $20,000 gift in 2007, which came because Trump used Trump Foundation money — earmarked for charity — to pay  $20,000 for a six-foot-tall painting of himself. On Wednesday, the man went digging back into old files to find a copy of the canceled check — so I could have the date right, and so I could see for sure that Trump had bought the painting with the charity's money. In the process of moving these old boxes of files, Ladika threw his back out terribly. When I talked to him late Wednesday, he was in pain and ready to go home — but he said he wouldn't leave until he was sure I had what I needed. I was amazed.

FIX: I’m a big fan of how you’ve married old school reporting (pen and pad to keep track of the Trump foundation donations) with the new world of social media (tweeting out pics of the list, asking various groups via Twitter if Trump ever gave them money). How did you settle on that approach to telling this story?

Fahrenthold: I settled on this technique out of desperation, basically. Back in May, Corey Lewandowski, Trump's then-campaign manager, told me that Trump had given out the $1 million he'd promised to veterans' charities — but Lewandowski said the details were secret. Trump would not say what groups he'd donated to, or in what individual amounts. I just had to trust Lewandowski. I didn't want to. But I couldn't call all of the thousands of veterans' groups in America individually. Instead, I started reaching out to the big vets' groups on Twitter, and including Trump's Twitter handle in all my inquiries. That way, other groups, other reporters — and Trump himself — could see what I was doing. I figured I would either shake the trees enough to find a few of Trump's donations — or, if Trump hadn't actually given the money, this would be enough to get his attention. What happened, it seems like, was the latter. After my Twitter search, Trump finally did donate the money that Lewandowski said he'd already given away.

Starting this summer, I set out to replicate that approach — and apply it to Trump's charitable giving more generally. By posting my list of charities on Twitter, I can let readers follow along, and offer suggestions about where I should look. And when I do find individual stories about Trump's interactions with individual charities, pictures of the list serve as a visual reminder that these small stories are all linked together.

FIX: Kellyanne Conway described your reporting as “badgering.” How would you describe it?

Fahrenthold: I've tried to be very transparent about what I know, what I don't, and what I've asked the Trump folks (and haven't gotten answers to). The Trump campaign generally does not respond at all to my requests for information — either requests for broader data on Trump's charitable giving, or narrow requests for information about specific subjects, like the $20,000 portrait of himself that Trump seems to have purchased with money from his charity. There's been a few exceptions to that rule, like a couple of weeks ago, when the Trump campaign told me that Trump had paid a penalty tax for giving a prohibited political gift out of the foundation's funds.

I don't think of myself as badgering them. But I do ask a lot of questions. I'm trying to treat every request that I send to them like it's my first request to them — meaning that I'm not coming in expecting a non-response, which means I'm not lowering the number or the scope of my questions because I think they won't be answered.