Mother Jones took on a hell of a challenge: trying to figure out how much money the fossil-fuel billionaire Koch brothers have spent on this election, and where.

In total, Koch Industries and its affiliates Georgia-Pacific and Flint Hills Resources have given more than $2.2 million to candidates and parties during this election cycle. Koch Industries recently asserted that its support for candidates “is not based on party affiliation, and we support both Republicans and Democrats who support market-based policies and solutions.” Yet 95 percent of its corporate donations in 2011 and 2012 have gone to Republicans.

If $2.2 million doesn’t sound like a lot (you know, relatively), there’s a reason why.

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Those figures establish the Kochs and their companies as significant, but not extraordinary, conservative donors. That’s where the accounting of their actual influence becomes tricky. As mentioned above, the Kochs have committed to raising millions to defeat Obama. However, most (if not all) of that money is going to outside-spending groups that don’t have to disclose their donors.

In California, the state’s Fair Political Practices Commission has been finding out just how difficult it is to trace donors to these shadowy groups. From the Los Angeles Times:

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After a frantic court battle, state election officials succeeded Monday in forcing an Arizona group to disclose the identities of contributors that provided $11 million to a California campaign fund.

But the revelations added little clarity for voters. The mystery donors turned out to be other nonprofits, whose individual contributors remained secret.

One of the California propositions at issue, Prop 30, would enact a temporary tax increase on people who earn more than $250,000 a year. You know who hates measures to tax the rich? The rich. And you know who hates having people know that they’re trying to subvert an election by pouring money into a political race? People trying to subvert an election by pouring money into a political race.

Given the focus of this L.A. Times article, you can probably guess what last name popped up in the California example.

The money started with the Virginia-based Americans for Job Security and was transferred to a group called the Center to Protect Patient Rights. Over the course of a few days in October it was sent to the Arizona group, Americans for Responsible Leadership, and then transferred again to California. …

The Center to Protect Patient Rights is run by Sean Noble, a key participant in the political activities of Charles and David Koch, the billionaire energy executives and GOP activists. During the 2010 midterm elections, the center was one of the primary conduits for anonymous political contributions, sending more than $55 million to 26 groups allied with Republicans, according to tax filings.

In a statement, a spokeswoman for Koch Industries said the Koch brothers were not involved in the California contribution.

“We have not contributed to any group with the intent of helping Proposition 32 or defeating Proposition 30 in California,” Melissa Cohlmia said.

Ms. Cohlmia likely wouldn’t cop to any Koch contribution even if it had been made. Donors go through these complex structures precisely so they can mask their identities. Alternate scenario: Someone just dropped off a bunch of money and drove away.

As Mother Jones notes, Charles and David Koch publicly pledged to spend $60 million over the course of the campaign. On the record, they’re about $57 million shy. Either they don’t want to put their money where their mouths are, or they don’t want you to see where they’re putting their money.

I’ll let you judge which is more likely.