Koch Brothers Net Worth Soars Past $100 Billion

Charles and David Koch hit a milestone on Wednesday, as a $1.3 billion boost to their collective fortune sent their net worth above $100 billion, according to Bloomberg News.

The brothers are majority stakeholders in Koch Industries, the second-largest privately held company in the U.S., after Cargill Inc. They are now the fifth- and sixth-wealthiest people in the world.

While half the country may not be familiar with the Koch brothers, according to a recent poll, the pair has poured millions into conservative campaigns and causes. The brothers' most recent advertising campaign will target key Senate races in Colorado and Iowa, chastising Democratic candidates Mark Udall and Bruce Braley for supporting the Affordable Care Act.

"The Koch brothers are pouring millions into our state because they know Congressman Cory Gardner (R) will fight for their interests, not Coloradans," Udall spokesman Chris Harris said in an email to The Huffington Post.

"Just like Bruce’s GOP opponents they support policies that would hurt Iowa’s economy, like blocking an increase in the minimum wage, undermining Medicare and Social Security, and sending us back to the days when insurance companies could kick people off their insurance when they got sick," Braley spokesman Jeff Giertz said in an email.

The brothers have faced the ire of Senate Majority Leader Harry Reid (D-Nev.) in recent weeks. Reid claimed the brothers are trying to "buy America." Charles Koch bit back in a recent op-ed in The Wall Street Journal.

"Rather than try to understand my vision for a free society or accurately report the facts about Koch Industries, our critics would have you believe we're 'un-American' and trying to 'rig the system,' that we're against 'environmental protection' or eager to 'end workplace safety standards,'" Koch wrote.

"Far from trying to rig the system, I have spent decades opposing cronyism and all political favors, including mandates, subsidies and protective tariffs -- even when we benefit from them. I believe that cronyism is nothing more than welfare for the rich and powerful, and should be abolished."