David Koch, in poor health, steps down from business and conservative political group

David Koch, the billionaire industrialist who combined his vast wealth and libertarian-tinged brand of conservatism to influence candidates at all levels of American politics, is stepping down from his political and business interests because of declining health, his company announced Tuesday.

Koch's brother, Charles, with whom he helped run Koch Industries, said in a letter to employees that health problems had made it impossible for David Koch to continue working. "Unfortunately these issues have not been resolved and his health has continued to deteriorate," the letter said. "We are deeply saddened by this."

The Koch family has been influential in conservative politics for generations, long before their name became synonymous with big money in the Republican Party. David Koch, in fact, was the vice presidential nominee for the Libertarian Party in 1980.

Using their powerful political group, Americans for Prosperity, they ramped up their political giving during the presidency of Barack Obama, whom Charles and David saw as seriously misguided and driven by a socialistic agenda that threatened the free-market philosophy they espoused. They played a pivotal role in the 2010 elections that put Republicans back into power in the House of Representatives.

They did not, however, see eye to eye with President Donald Trump and have dialed back their political efforts over the last couple of years. Once Trump became the Republican nominee in 2016, they shifted their political giving away from the presidential campaign to focus exclusively on Congressional races.

David Koch has also been a generous donor to the arts in New York, contributing $100 million in 2008 to New York City Ballet's Lincoln Center theater — which was then named after him — and $65 million in 2014 to the Metropolitan Museum of Art for the refurbishment of its fountains plaza.

"David has always been a fighter and is dealing with this challenge in the same way," Charles Koch said in his letter.