A small group of ultra-wealthy Americans pumps a lot of money into politics.
We took a look at the top 25 donors who funded American politics in 2018 and found that the list consists of, among others, an assortment of financiers, heirs, and entrepreneurs.
The contributions of some of the largest donors — such as Sheldon and Miriam Adelson, George Soros and Tom Steyer— are well known, while other donors, like Jeff Bezos, are better known for their careers.
Interestingly, one well-known political donors — Charles Koch— did not make the list. Koch and his now-deceased brother David donated $1,816,650 to Republicans through their company Koch industries in 2018, according to The Center for Responsive Politics. To make this list, their donations would have needed to top $6.5 million.
Business Insider previously reported that public affairs rank as the eighth-most popular cause that billionaires donate to. Only 12.4% of billionaires reported making donations to politics in 2018, according to Wealth-X's 2019 Billionaire Census.
Collectively, the 25 billionaires and billionaire couples on the list totaled a whopping $573,892,284 in political donations in 2018, data from The Center for Responsive Politics shows.
Keep reading to learn more about the country's biggest political donors, ranked in order of their donations during the 2018 election cycle by The Center for Responsive Politics. Each donor's net worth, where available, was sourced from Forbes unless otherwise specified. Their party affiliations are listed according to The Center for Responsive Politics.
SEE ALSO: Meet the 18 ultra-wealthy Americans begging for a wealth tax, from a Facebook cofounder to a Disney heiress
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25. Billionaire hedge-fund manager Paul Singer gave $6.4 million to Republicans, according to the Center for Responsive Politics.
Total donations: $6,463,400
Party: Republican
Net worth: $3.5 billion
Singer is the founder of investment firm Elliott Management, according to his biography on the firm's website, but he is better known for his advocacy for conservative causes, Forbes reports. Once a major critic of President Trump, Singer has since met with him at the White House. Singer does break with the President on one important issue, however — Singer is also an advocate for LGBTQ+ rights.
24. Former Breitbart News investor Robert Mercer and his wife Diana have given $6,544,024 to conservatives.
Total donations: $6,544,024
Party: Republican
Net worth: Unknown
Robert Mercer, 73, is the former co-CEO of Renaissance Technologies, a hedge fund valued at $50 million in 2017, according to The New York Times. Mercer left the hedge fund in 2017 after clients, including the retirement fund for Baltimore's police and firefighters, withdrew their investments from Renaissance over concern about Mercer's political donations and involvement with Breitbart, The Times reported.
The $6.5 million that Robert and his wife Diana donated to Republicans in 2018 was the smallest figure they've given in any election cycle since 2012, CNBC reported. The couple, once among President Trump's biggest supporters, have become fatigued by the resulting media attention, sources told CNBC.
23. CEO of Arkansas-based chicken producer Mountaire Corp, Ronald Cameron, and his wife Nina donated nearly $6.6 million to Republicans.
Total donations: $6,574,352
Party: Republican
Net worth: Unknown
Ronald Cameron is the CEO of the poultry company founded by his grandfather, according to the North Caroline Poultry Foundation. Mountaire Corp is the seventh-largest producer of chicken in the country, the foundation reports. An alum of the University of Arkansas, Ronald and his wife Nina have four children and nine grandchildren, according to the foundation's website.
The Camerons were responsible for 80% of total donations to Mike Huckabee's 2016 presidential run, ABC News reported.
22. Indiana real-estate developer Paul Skjodt and philanthropist Cynthia Simon-Skjodt gave $6.8 million to Democrats through their foundation.
Total donations: $6,750,150
Party: Democrat
Net worth: Unknown
Cindy Simon-Skjodt serves as the chair of the couple's non-profit, the Samerian Foundation, according to its website. The foundation provides grants for education, economic development, and youth sports initiatives, according to its website. Paul Skjodt is a former professional hockey player and real estate developer, according to his biography on the foundation's website.
The Skjodts donated $20 million to create a genocide prevention center at the United States Holocaust Memorial Museum in Washington, D.C. in 2015, according to The Indianapolis Business Journal.
21. Jeffrey and Janine Yass donated $7.3 million to conservatives.
Total donations: $7,611,083 ($7,295,833 to conservatives, $250 to liberals)
Party: Republican
Net worth: Unknown
Jeffrey Yass is a cofounder of trading firm Susquehanna International Group, according to the company's website.
The couple also donated $250 to liberals in addition to their support of conservatives, according to the Center for Responsive Politics.
20. Investor Joshua Bekenstein and philanthropist Anita Bekenstein gave $7.7 million to Democrats.
Total Donations: $7,713,540
Party: Democrat
Net worth: Unknown
Joshua Bekenstein is the co-chairman of Bain Capital, the private equity firm cofounded by Mitt Romney, according to Fortune.
Anita, Joshua's wife, is a philanthropist who manages the couple's private fund, which supports health, education, arts, and environmental non-profits, in addition to serving on the board of patient advocacy non-profit Upstream USA, according to her biography on the organization's website.
The couple lives in Boston and has five children, according to Anita's biography on the organization's website.
19. Facebook cofounder Dustin Moskovitz and his wife, former Wall Street Journal reporter Cari Tuna, donated $7.7 million to Democrats.
Total donations: $7,720,230
Party Affiliation: Democrat
Net worth: $11.8 billion
After leaving Facebook in 2008, Dustin Moskovitz founded workflow management platform Asana, according to Forbes.
Alongside his wife Cari Tuna, Moskovitz has donated millions to health and LGBTQ+ organizations through their foundation Good Ventures, Forbes reports.
Moskovitz maintains a 3% stake in Facebook, according to Forbes.
18. Home Depot cofounder Bernard Marcus and his wife, Billi Wilma, gave nearly $8 million to Republicans.
Total donations: $8,000,018 ($7,980,318 to conservatives, $500 to liberals)
Party Affiliation: Republican
Net worth: $6.5 billion
Bernie Marcus cofounded Home Depot in 1978 with Arthur Blank after they were fired from their jobs at another hardware store, according to Forbes. Marcus was the company's first CEO and retired in 2002.
Marcus was a major contributor to President Trump's 2016 presidential bid and will support the President again in 2020, Business Insider previously reported.
Read more: The billionaire cofounder of Home Depot plans on donating up to 90% of his $5.9 billion fortune, and Trump's 2020 campaign will be one of the beneficiaries
17. Charles Schwab, the founder of the eponymous brokerage firm, and his wife Helen gave $8,531,440 to Republicans.
Total donations: $8,531,440
Party Affiliation: Republican
Net worth: $8.2 billion
Charles Schwab, 81, founded his brokerage firm in 1971 and served as its CEO until 2008, according to Forbes. Schwab's fortune comes from his 11% stake in the firm.
Helen is a philanthropist and serves as the president of the board of the Charles and Helen Schwab Foundation, according to the organization's website.
The couple resides in Woodside, California and has 5 children, according to Forbes.
16. LinkedIn cofounder Reid Hoffman donated $9,315,826, mostly to Democrats.
Total donations: $9,315,826 ($433,500 to conservatives, $8,317,326 to liberals)
Party Affiliation: Democrat
Net worth: $1.9 billion
Reid Hoffman was an early employee of PayPal and one of the first investors in Facebook, according to Forbes. Hoffman founded Linkedin in 2003. Hoffman sold LinkedIn for $26.2 billion to Microsoft in 2016 and now sits on Microsoft's board, according to Forbes.
Hoffman gave $8,317,326 to Democrats and $433,500 to Republicans in 2018, according to the Center for Responsive Politics.
15. Investor George Marcus and his wife Judith gave $9,610,125, mostly to Democrats.
Total donations: $9,610,125 ($10,400 to conservatives, $9,579,725 to liberals)
Party Affiliation: Democrat
Net worth: $1.5 billion
George Marcus is the founder of real-estate brokerage Marcus & Millichap Company, according to the company's website. Marcus is also the chairman of Essex Property Trust, a multi-family real-estate investment trust, and he serves on the board of California-based commercial bank Greater Bay Bancorp.
The Marcuses gave $10,400 to Republicans in 2018, according to the Center for Responsive Politics. The rest went to Democrats.
14. Heiress Deborah Simon donated $9.7 million to Democrats.
Total donations: $9,744,070
Party Affiliation: Democrat
Net worth: Unknown
Deborah Simon is the daughter of Indiana shopping mall developer Melvin Simon. Simon inherited a portion of her father's fortune after a bitter legal battle over his estate with her stepmother Bren Simon, according to Forbes.
Simon's family had a net worth of $6.8 billion in 2014, according to Forbes.
13. Investor Timothy Mellon gave $10 million, mostly to Republicans.
Total donations: $10,061,000 ($10,058,300 to conservatives, $2,700 to liberals)
Party Affiliation: Republican
Net worth: $1 billion
Timothy Mellon, the grandson of twentieth-century business magnate Andrew Mellon, funded the founding of New Hampshire-based railroad company, Guilford Transportation Industries, according to Forbes.
While most of Mellon's donations were to conservatives, Mellon also gave $2,700 to Rep. Alexandria Ocasio-Cortez, according to The Guardian.
12. Jeff and MacKenzie Bezos donated $10,186,170 in total to candidates of both parties.
Total donations: $10,186,170
Party Affiliation: Non-partisan, lean conservative
Net worth: $107.4 billion, $33.9 billion
Amazon CEO Jeff Bezos and novelist MacKenzie Bezos made 60% of their donations to Republicans and 40% of their donations to Democrats, according to The Center for Responsive Politics.
The pair finalized their divorce in July 2019, Business Insider previously reported.
Read more: 25 years after Amazon's launch, Jeff Bezos is the richest person alive. Here's how he makes and spends his billions.
11. California-based psychiatrist Karla Jurvetson donated $12 million to Democrats.
Total donations: $12,431,198 ($5,400 to conservatives, $12,415,726 to liberals)
Party Affiliation: Democrat
Net worth: Unknown
Karla Jurvetson is the ex-wife of venture capitalist Steve Jurvetson, according to The Guardian. Her largest donation, $5.4 million, was to a Super PAC aimed at elected pro-choice female candidates run by Emily's List, The Guardian reported.
10. Chicago-based newspaper publisher Fred Eychaner gave $12,665,400 to Democrats.
Total donations: $12,665,400
Party Affiliation: Democrat
Net worth: $500 million in 2005
Fred Eychaner is the chairman of Newsweb Corp. Eychaner became wealthy after selling a television station to Rupert Murdoch's NewsCorp for $425 million in 2002, according to Crain's Chicago Business.
Eychaner is also a major supporter of Hillary Clinton. He financially backed her 2008 and 2016 presidential bids, according to Crain's Chicago Business.
9. Blackstone Group CEO Stephen Schwarzman and his wife Christine gave $12,882,200 to Republicans.
Total donations: $12,882,200
Party Affiliation: Republican
Net worth: $16.7 billion
Stephen Schwarzman, 72, cofounded the private equity firm in 1985, according to Forbes.
8. Hedge-fund manager Kenneth Griffin donated $19,225,125 to Republicans.
Total donations: $19,225,125
Party Affiliation: Republican
Net worth: $12.7 billion
Ken Griffin is the founder and CEO of Chicago-based hedge fund Citadel, according to The Guardian. Citadel manages $32 billion in assets, according to Forbes.
Griffin also owns the most expensive apartment ever sold in New York City, Business Insider previously reported.
Read more: Hedge-fund manager Ken Griffin's $238 million NYC apartment shattered the US real estate record — here's a look at his record-setting properties and penthouses
7. Billionaire financier George Soros donated over $20 million to Democrats.
Total donations: $20,135,586
Party Affiliation: Democrat
Net worth: $8.3 billion
Soros built his fortune leading Quantum Fund, once the world's largest hedge fund. Since retiring from money managing in 2011, Soros has turned his attention to philanthropy. He started donating to campaigns in 2003 because of his dissatisfaction with the war in Iraq, Business Insider previously reported.
Soros has also found himself at the center of numerous conspiracy theories about his involvement in governments from the United States to Hungary to Russia, many of which are anti-Semitic and have never been supported by evidence.
Read more: What George Soros' life is really like: How the former hedge-fund manager built his $8.3 billion fortune, purchased a sprawling network of New York homes, and became the topic of international conspiracy theories
6. James and Marilyn Simons gave $22 million to Democrats.
Total donations: $22,165,010
Party Affiliation: Democrat
Net worth: $21.6 billion
James Simons, the founder of quantitative hedge fund Renaissance Technologies, was named the highest-paid hedge fund manager of 2019 by Forbes. James and his wife, economist and philanthropist Marilyn Simons, are also major donors to Stony Brook University, where they met, according to Bloomberg.
5. Hedge-fund manager S. Donald Sussman donated over $27 million to Democrats in 2018.
Total donations: $27,545,500
Party Affiliation: Democrat
Net worth: Unknown
Donald Sussman is the founder of Paloma Partners. The Fort Lauderdale-based hedge fund was the top donor to Hillary Clinton's 2016 presidential campaign, giving $21.6 million, according to The Guardian.
4. Uline CEO Richard Uihlein and his wife Elizabeth donated almost $40 million to Republicans.
Total donations: $39,854,296
Party Affiliation: Republican
Net worth: Between $700 million and $2 billion in 2014
Richard Uihlein is the founder of the Wisconsin-based shipping materials company Uline, according to Forbes.
"I'm a conservative Republican, and I'm trying to help people who believe as I do in limited government and free markets," Richard Uihlein said in 2013, according to Forbes. "I'm not one to hide from that."
3. Presidential candidate Tom Steyer and his wife Kathryn Taylor gave $73,819,973 to Democrats.
Total donations: $73,819,973
Party Affiliation: Democrat
Net worth: $1.6 billion
Tom Steyer, 62, ran hedge fund Farallon Capital before becoming a full-time activist in 2012, according to Forbes.
Read more: Billionaire activist Tom Steyer just jumped into the 2020 Democratic field after previously ruling out a presidential run
2. Former New York mayor Michael Bloomberg donated over $95 million, nearly all of it to Democrats.
Total donations: $95,098,168 ($5,400 to conservative, $94,837,766 to liberals)
Party Affiliation: Democrat
Net worth: $52.4 billion
Michael Bloomberg, 77, is the founder and CEO of financial media company Bloomberg LP.
Bloomberg will spend $500 million on the 2020 election in hopes of defeating Trump, Politico reported in February. On November 7, The New York Times reported that he was actively preparing to enter the Democratic primary.
1. Sheldon and Miriam Adelson gave $123,244,400 to Republicans.
Total donations: $123,244,400
Party Affiliation: Republican
Net worth: $33.6 billion
Sheldon Adelson, 86, is the CEO of the Las Vegas Sands casino company, according to Forbes. Adelson is also an avid Trump supporter. Adelson was the largest donor to both Trump's 2016 presidential campaign and his inauguration fund, according to The Guardian.