The political activities of the Koch brothers include the financial and political influence of Charles G. and David H. Koch on United States politics. This influence is seen both directly and indirectly via various political and public policy organizations supported by the Koch brothers.
The Koch brothers are the sons of Fred C. Koch, who founded Koch Industries, the second-largest privately held company in the United States, of which they own 84%. Having bought out two other brothers' interests, they remain in control of the family business, the fortune which they inherited from their father, and the Koch family foundations.
The brothers have made significant financial contributions to libertarian and conservative think tanks and campaigns. Their network of groups pledging to spend $889 million from 2009–2016 and its infrastructure has been said by Politico to rival "that of the Republican National Committee." They actively fund and support organizations that contribute significantly to Republican candidates, and in particular that lobby against efforts to expand government's role in health care and combat global warming. By 2010, they had donated more than $100 million to dozens of free-market and advocacy organizations.
The phrase "Koch brothers" generally refers to the sons of Fred C. Koch. The most politically active sons are Charles Koch and David H. Koch who bought out their brothers Frederick and Bill in 1983.
David H. Koch was the Libertarian Party's vice-presidential candidate in 1980. He advocated for the abolition of Social Security, the FBI, the CIA, and public schools. Koch put $500,000 of his own money into the race, and he and Ed Clark, his presidential running mate, won 1.1% of the vote. The experience of running for office caused David Koch to change course: "I had enough ... [W]e are not a nation that debates issues. We vote on candidates' personalities." By 1984, David had parted company with the Libertarian Party, because, he said, "they nominated a ticket I wasn't happy with" and "so many of the hard-core Libertarian ideas are unrealistic."