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Rich people of all political stripes pour money into politics. Few are as private about it as Robert Mercer. He's the co-CEO of the hedge fund Renaissance Technologies. Mercer and his daughter are big supporters of President Trump. Their own agenda remains something of a mystery. NPR's Jim Zarroli reports.
JIM ZARROLI, BYLINE: At 70, Robert Mercer is very much an American success story, someone who went from middle class to super rich with dizzying speed. His entry onto the political scene has been just as fast. Sheila Krumholz of the Center for Responsive Politics says Mercer donated $25 million to candidates and causes last year, making him the country's eighth-biggest donor.
SHEILA KRUMHOLZ: Even though he's very private, he has very deep pockets. And he cuts a wide swath in conservative politics.
ZARROLI: Krumholz says virtually all of Mercer's money went to conservative causes. He backed Texas Senator Ted Cruz for president before switching to Trump. Mercer rarely speaks publicly, but in a 2014 address, he reminisced about working in a very early computer lab as a young man.
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ROBERT MERCER: Perhaps the most important thing that I learned was that I really loved everything about computers. I loved the solitude of the computer lab late at night. I loved the air-conditioned smell of the place. I loved the sound of the disks whirring and the printers clacking.
ZARROLI: Mercer told the audience he sees himself as a computer programmer, but that's false modesty. After a career at IBM, Mercer moved to the hedge fund Renaissance Technologies in the 1990s. Nick Patterson, who helped hire Mercer, says Renaissance wanted to use complex mathematical models to make market trades, and Mercer and a colleague were instrumental in helping design them.
NICK PATTERSON: Their primary work was to look very, very hard at equity trading. And after some effort, some several years of effort, they were able to produce a system which was hugely profitable.
ZARROLI: Patterson says even then Mercer had strong political views.
PATTERSON: They were very, very conservative, I mean, libertarian. If I wanted to use a prejudicial word, I'd probably say they were reactionary.
ZARROLI: For instance, Mercer was skeptical about climate change. And Patterson says he stood out in another way.
PATTERSON: He really, really hated Bill and Hillary Clinton, and he was quite vocal about that.
ZARROLI: Do you remember what he said?
PATTERSON: Yes. He thought that Bill, at any rate, was a murderer.
ZARROLI: A murderer?
PATTERSON: Yeah, a murderer and a rapist.
ZARROLI: In recent years, Mercer's money has made him a political force. He's part owner of the right wing website Breitbart and helps fund the data mining company Cambridge Analytica. His daughter Rebekah, who's been called the most powerful woman in Republican politics, served on President Trump's transition team.
But the Mercers' political agenda is murky. McClatchy News reported this month that Renaissance is fighting with the IRS over what are called basket options. Edward Kleinbard is a professor of law at the University of Southern California.
EDWARD KLEINBARD: There's an awful lot at stake, both in terms of the unpaid tax, but now also in terms of penalties because the IRS, you know, takes the view that these are abusive tax shelters.
ZARROLI: Mercer has donated to groups seeking to depose the IRS commissioner, but the Mercers' real loyalties are hard to pin down. He and his daughter were said to be furious with Republican leaders after Mitt Romney's defeat in 2012. For now, they remain supporters of the president, but they've made clear they're not afraid to cut ties with the GOP if it goes in a direction that displeases them. Jim Zarroli, NPR News, New York.
(SOUNDBITE OF MR. GREEN SONG, "COMEBACK") Transcript provided by NPR, Copyright NPR.