David Koch, the nationally known billionaire conservative financier and industrialist, had died. He was 79.
"It is with a heavy heart that I announce the passing of my brother David," Charles Koch said in a statement Friday. "Anyone who worked with David surely experienced his giant personality and passion for life."
David, whose net worth of about $42.2 billion tied him with his brother as the world's 11th-richest person in a ranking by Forbes, gained most of his wealth from a 42 percent stake in the Kansas-based energy and chemical company, Koch Industries, which he co-owned with his brother since 1983. The global family enterprise has interests ranging from oil to beef to fertilizer to paper and is the nation's second-largest privately-held company.
David stepped down from his position as executive vice president of Koch Industries and other Koch-affiliated groups last year due to his declining health. Charles remains the company's chairman and chief executive officer, a role he has held since 1967.
Although he was on the liberal side of social issues like abortion and same-sex marriage, David used his fortune to champion conservative causes that favor lowering taxes, free trade and deregulations. He was the vice-presidential candidate of the Libertarian Party in 1980.
With the wealth from their business, the Koch brothers developed a massive network of mega-donors for conservative organizations that work to mobilize voters and influence elected officials, judicial appointments and lobbyists in support of libertarian policies.
The network, led by the nonprofit Americans for Prosperity, has spent more than $1 billion over the past several elections to promote candidates that embrace their free-market, small government vision while also donating to philanthropic causes. Critics have accused the Kochs of using their extraordinary wealth and political machine to manipulate elections and policy outcomes, weakening democracy under a guise of patriotism and philanthropy that benefits their bottom line.
The Kochs have been credited with helping finance the conservative Tea Party movement and fueling the far-right wing of the Republican Party. Analysts have said the brothers played a significant role in helping Donald Trump clinch the presidency in 2016.
Although the brothers did not endorse Trump, David attended his election night victory party and later met with the president-elect at his Mar-a-Lago resort in Palm Beach, Florida. The Kochs contributed heavily to Vice President Mike Pence's two campaigns for governor of Indiana and a half-dozen veterans of the Koch political arm worked on the Trump campaign — from top Pence aide Marc Short to former chief strategist Steve Bannon, ex-White House counselor Don McGahn and former campaign aides Stuart Jolly, Eli Miller, Stuart Hagerstrom, Charles Munoz and Matt Ciepielowski.
Ahead of the 2018 midterm election cycle, the Kochs broke with the Republican Party under Trump. They launched a multi-million dollar campaign last year to promote free trade and warn against tariffs. Trump fired back on Twitter, calling the Koch political operation "overrated" and a "total joke in real Republican circles."
David Koch was diagnosed with prostate cancer more than 20 years ago. Since then, he and his family foundation, along with other beneficiaries of the Koch network, have donated hundreds of millions of dollars to medical research, especially fighting cancer.
He was also a huge supporter of the arts in New York, notably contributing to Lincoln Center and $65 million to support a renovation of the Metropolitan Museum of Art.
Koch was diagnosed with cancer 27 years ago, and he was given five years to live at the time, his brother said.
"David liked to say that a combination of brilliant doctors, state-of-the-art medications and his own stubbornness kept the cancer at bay," Charles Koch said in his statement. "We can all be grateful that it did, because he was able to touch so many more lives as a result."
"The significance of David's generosity is best captured in the words of Adam Smith, who wrote, 'to indulge our benevolent affections, constitutes the perfection of human nature,'" Charles said.
David Koch is also survived by his wife, Julia, and three children.
"While we mourn the loss of our hero, we remember his iconic laughter, insatiable curiosity, and gentle heart," Julia said in a statement.
"His stories of childhood adventures enlivened our family dinners; his endless knowledge rendered him our ‘walking Google.’ His sensitive heart had him shed a tear at the beauty of his daughter’s ballet, and beam with pride when his son beat him at chess," she wrote. "We will miss the fifth link in our family."