Charles and his late brother, David, used their collective wealth and connections to wield incredible political influence over the past few decades, donating hundreds of millions of dollars to reshape the American political landscape, push the Republican agenda towards their Libreterian, free-market bend, and give rise to the Tea Party movement. Together, the brothers founded the conservative powerhouse Americans for Prosperity in 2004.

“Boy, did we screw up!,” wrote Koch, now 85, in his new book, Believe in People: Bottom-Up Solutions for a Top-Down World. “What a mess!"

Koch and his brother were also largely involved in shaping the country’s response to climate change. Through Americans for Prosperity, they got over 400 members of Congress to sign a pledge to vote against climate change legislation that does not include equivalent tax cuts. In California, they were influential in rolling back emission regulations, and between 1997 and 2018 they spent $145,555,197 financing nearly 100 groups that attacked climate change science.

Following the 2011 Supreme Court Citizens United decision, the Kochs spent nearly $200 million to elect Republicans who said that they would not pass any new environmental regulations.

"We did not create the tea party. We shared their concern about unsustainable government spending, and we supported some tea-party groups on that issue," Koch wrote in an email to Wall Street Journal reporter Douglas Belkin on November 13. "But it seems to me the tea party was largely unsuccessful long-term, given that we're coming off a Republican administration with the largest government spending in history."

He also congratulated President-elect Joe Biden and vice president-elect Kamala Harris and said he’d like to collaborate with the new White House on "finding ways to work with them to break down the barriers holding people back." Those barriers, he said, include criminal justice and immigration reform.

"At the same time," Koch wrote in his email, "I hope we all use this post-election period to find a better way forward. Because of partisanship, we've come to expect too much of politics and too little of ourselves and one another."

Though the Kochs did not support Trump, they poured about $750 million into the 2016 election. In 2018, they pledged to spend another $400 million to back conservative candidates.