Libertarian philanthropist Charles Koch has found common ground with one of his biggest critics: Democratic presidential candidate Bernie Sanders.

In an op-ed for the Washington Post, the billionaire mega-donor wrote that he and Sanders agree on the importance of amending "a political and economic system that is often rigged to help the privileged few at the expense of everyone else, particularly the least advantaged."

"[Sanders] believes that we have a two-tiered society that increasingly dooms millions of our fellow citizens to lives of poverty and hopelessness," Koch wrote. "He thinks many corporations seek and benefit from corporate welfare while ordinary citizens are denied opportunities and a level playing field."

"I agree with him," he added.

According to Koch, both major political parties have a penchant for "policies and regulations that pick winners and losers." He claims such policies "perpetuate a cycle of control, dependency, cronyism and poverty" in the U.S.

"Whenever we allow government to pick winners and losers, we impede progress and move further away from a society of mutual benefit. This pits individuals and groups against each other and corrupts the business community, which inevitably becomes less focused on creating value for customers," he wrote.

Koch also highlighted criminal justice reform as an issue on which he and the socialist senator might find that their opinions overlap.

"Today, if you're poor and get caught possessing and selling pot, you could end up in jail. Your conviction will hold you back from many opportunities in life," he wrote. "However, if you are well-connected and have ample financial resources, the rules change dramatically. Where is the justice in that?"

Sanders has weaved criminal justice reform into his stump speech on the campaign trail and has focused even more on the issue in recent weeks given the large role African-American voters will play in the upcoming South Carolina Democratic primary.

The Vermont senator has described the criminal justice system as "broken" and called for an end to mandatory minimum sentences for non-violent drug offenders and for additional investments in "jobs and education, not more in jails."

While Koch said he is "hardly" a Sanders supporter, he applauded the Democratic candidate "for giving a voice to many Americans struggling to get ahead in a system too often stacked in favor of the haves."

"But I disagree with his desire to expand the federal government's control over people's lives. This is what built so many barriers to opportunity in the first place," he noted.

Koch has previously said it is unlikely that he will endorse a candidate in the presidential primary and in his op-ed for the Post he maintained that he is still searching for someone who's able to earn his "enthusiastic support."