Charles and David Koch, billionaire conservative brothers who are known to support conservative candidates, as well as groups that deny climate change, run a donor network that vowed in January to spend up to $400 million in the midterm elections to support conservative candidates and policies, according to Bloomberg.

This amount marks a 60 percent increase from the approximately $250 million the Koch network spent during the 2016 election cycle. The Koch network has pledged to outraise the Republican National Committee by at least $150 million during the midterm elections.

David Koch announced his retirement in June, citing his declining health, leaving Charles Koch the sole brother at the center of Koch Industries.

The Charles Koch Foundation at Chapman
The Charles Koch Foundation donated $5 million to Chapman in December 2016to help establish the Smith Institute for Political Economy and Philosophy, which aims to combine the studies of humanities and economics. The donation has ignited controversy at Chapman, with some faculty calling for more transparency around the foundation’s agreement with the university.
The foundation donates millions to universities and colleges across the nation to create a “talent pipeline” of libertarian-minded students, according to the Center for Public Integrity.

Candidates the Koch network supports
The Koch-affiliated super PAC, Americans for Prosperity Action, had spent more than $5 million on the midterm elections as of Oct. 28. Half went to supporting Republican candidates and half went to opposing Democratic candidates, according to data from the Federal Elections Commission. But Charles Koch warned an audience at a donor retreat in July that Republican candidates shouldn’t expect backing from the foundation unless they support free market ideals and oppose government spending.

Among the candidates supported by the super PAC is Marsha Blackburn, a hard-line Republican running for senate in Tennessee, a state that went to President Donald Trump by 26 points in 2016. Blackburn once claimed that Planned Parenthood was selling “baby body parts on demand,” according o the New York Times.

How their donations measure up
Americans for Prosperity Action ranks at No. 19 for most money spent out of more than 2,000 super PAC in the election cycle, according to the Center for Responsive Politics, giving the network significant financial leverage in supporting certain candidates. Like Americans for Prosperity Action, more than 55 percent of the super PACs that have spent money for the 2018 midterms are conservative. Nearly $355 million has been raised by conservative super PACs, compared to $255 million for Democratic ones.

Despite the brothers’ support of traditionally conservative candidates, they have also drawn criticism from Trump after their Freedom Partners nonprofit, which supports free markets, ran a six-video campaign in July titled “Trade not aid,” which criticized Trump’s import tariffs. Trump responded by tweeting that the brothers are a “joke” in Republican circles and said he has never sought their support.

Tim Phillips, president of Americans for Prosperity, declined to comment on Trump’s criticism of the Koch brothers in July, according to the New York Times.

“We’re focused on advancing policies that break down barriers to success for Americans, not on personal attacks,” Phillips said.