Paul Singer is a billionaire hedge fund manager and one of the most prolific Republican donors in the country. In addition to his personal giving, Singer also “has a vast network of people who will give” to candidates he endorses – for instance, the New York Times Frank Bruni reported that Singer raised $5 million for Mitt Romney in a single May 2012 fundraiser. CNN referred to him as “perhaps the [GOP’s] most prodigious fundraiser” and the New York Timesconfirms that Singer “provides something that some other coveted Republican donors do not… Mr. Singer is an effective ‘bundler’ for candidates.” Singer made headlines in October 2015 for pledging his support to Sen. Marco Rubio’s 2016 presidential bid, despite attempts by Govs. Jeb Bush and Chris Christie to secure Singer’s endorsement.

Multiple sources claim that Singer cares primarily about two issues: promoting a strong relationship with Israel, and gay rights. According to the New York Times, however, Singer “is generally viewed as a donor who does not believe in litmus tests,” which presumably benefits Sen. Rubio, who “disagreed” with the Supreme Court’s decision to legalize same-sex marriage nationwide at the same time as Singer was spending millions to create American Unity PAC, with a “sole mission… to encourage Republican candidates to support same-sex marriage.” Singer told the New York Times that it would be “naïve” of him to “take this issue and just upend everything else I believe,” explaining his continued support for anti-gay candidates.

On other issues, Singer more than toes the GOP party line. Fortune writes, “In hedge fund circles, the joke about Singer used to be that he was ‘to the right of Attila the Hun,’ given his devotion to Republican ideology.” With a net worthof more than $2 billion and a company – Elliott Management Corporation – worth more than $23 billion, Singer is a “passionate defender of the 1%” according to the profile by Fortune. In a letter to investors, Singer described income inequality as a “wedge issue.” Perhaps most tellingly, Fortune reports:

The billionaire shows little sympathy for the plight of the 99%. “Resentment is not morally superior to earning money,” writes Singer.

When it comes to his business, Singer has a distinct method of operating which has drawn significant criticism – Elliot Management Corporation’s hedge fund operation is an infamous example of a “vulture fund.” Hedge Clippersdescribes a vulture fund’s operating model as such:

Buying up the debt of bankrupt or struggling countries and companies at a deep discount (often for pennies on the dollar), and then demanding that the debt be paid in full. Vulture funds often become “hold outs”—refusing to agree to debt restructuring and other compromises proposed by often-desperate debtor companies and countries. Then they collect by taking their debtors to court—in the case of debtor nations, sometimes to courts all over the world.

As the globe has increasingly offered debt relief as development aid to poor countries, “the vulture funds, a club of between 26 and 35 speculators, have ignored… pleas from the likes of the World Bank and International Monetary Fund to give the countries a break and a chance to get back on their feet,” according to the Guardian. The World Bank reported that vulture funds “have managed to collect $1bn from the world’s poorest countries and still have a further $1.3bn to collect,” which the Guardian notes could “fund the entire UN appeal for the famine in Somalia” and was more than twice the amount of the Red Cross’s 2011 budget for all of Africa. Singer has remained “unapologetic” regarding criticism of vulture funds, per the Nation.

One example in particular shows the lengths Singer will go to in order to extract payment from preyed-upon countries: Elliot Associates has been unrelenting in their “drive to extract full compensation” from the defaulted Argentinian government for over a decade after purchasing over a billion dollars in debt in 2001, pursuing “the country’s assets around the globe.” In 2012 the firm even got a Ghana court to detain an Argentinian naval vessel while it was in the Ghanaian port city of Tema. The firm and other bond holders also have attempted to seize Argentina’s presidential airplane while it was in the U.S., gone after the personal assets of Argentine politicians, and even threatened to seize the display Argentina was preparing at the Frankfurt Book Fair. Elliot also backs American Task Force Argentina, a lobbying group established “to draw attention to Argentina’s misbehavior,” even though some of the members it claims to represent had never heard of the group.  Fears of the group’s tactics have had such influence they “helped shape” how Greece restructured its debt.

An analysis of Singer’s political spending reveals both that he expects a return on his investment and the central role he plays in funding conservative politics. As Hedge Clippers reports, 12 Members of Congress who received a combined $200,000 from Singer and Singer-connected PACs wrote a letter to Attorney General Eric Holder in 2013, urging Holder to side with Singer’s hedge fund in its protracted battle against Argentina.

Singer is also a member of the Koch brothers’ network of ultra-rich, ultra-conservative donors, although it’s worth noting that Bloomberg instead describes David Koch as a member of the Singer network. Singer donations have gone to Koch brother entities such as the American Future Fund, and Singer has attended or sent proxies to the Freedom Partners-hosted confabs, where the Kochs lay out their political goals for donors. Singer has also contributed outside the Koch network, notably gifting American Crossroads more than $2 million dollars, giving the Ricketts’ family’s Ending Spending Action Fund more than $3 million, contributing to various Republican Party entities, and giving to Club for Growth Action & Citizens Club for Growth. Singer is additionally one of the seed funders of Future45 and the 45Committee, two new groups dedicated to attacking former Secretary of State Hillary Clinton.