Charles Koch. Photo: Bo Rader/Wichita Eagle/MCT via Getty Images

Charles and David Koch once pledged to spend $889 million on the 2016 campaign cycle. Now the billionaire brothers plan to stay on the sidelines of this year’s presidential race — and have cut their paid media budget for all of this cycle’s campaigns to $40 million, down from $150 million one year ago. While many have interpreted the Kochs’ sudden stinginess as a rebuke to the less-than-libertarian Republican nominee, a new report from the National Review suggests the tycoons are fundamentally rethinking their approach to rigging the system.

The magazine’s story opens at a February meeting of the Koch network’s top political operatives. Trump had just won the New Hampshire primary, and Freedom Partners president Marc Short had prepared a plan to halt the Donald’s rise. But when Short arrived at the summit he was confronted by an unwelcome surprise: The Koch’s “corporate wing” had been invited.

The suits at Koch Industries had never been crazy about the brothers’ campaign spending and the public-relations nightmares it routinely generated. When Charles Koch decided to poll the room on Short’s plan, its fate was inevitable: The Kochs would sit out the primary. A month later, they announced they’d probably be sitting out the fall presidential contest altogether. Now they appear to be cutting back on their down-ballot spending as well.

According to the National Review, the Koch network has spent $10 million in paid media on this year’s Senate races — at this point in 2014, they’d spent more than $35 million. In those midterms, the Kochs funded ad campaigns in 11 Senate contests; in 2016, they’re involved in just 4.

Some reasons for this drawback are cycle-specific: A lot of big-money donors have a fetish for presidential politics, and when the Kochs announced they had no interest in backing Trump, their fundraising took a hit. Plus, with the Donald’s unfavorability handicapping GOP Senate candidates, the Kochs are reluctant to bet big money on Republicans keeping the upper chamber.

But the brothers are also getting tired of being the poster boys for plutocracy. Last October, Charles made the media rounds to promote his book Good Profit, which detailed the high-minded principles that guide Koch Industries. Much to his horror, the only thing the media wanted to talk about was how he was trying to buy the government.

The Koch network began inviting reporters to its exclusive donor retreats for the first time last year, and Charles embarked on a media blitz to promote the book. What he encountered was eye-opening: Despite his remarkable business career and decades-long involvement in other philanthropic initiatives, questions centered around one topic: his putative role as the GOP’s puppet master.

The Kochs’ communications department had long warned that their conspicuous political spending would erode the corporate brand. Charles finally believed them.

Before 2010, the Kochs were content to advance their self-serving brand of libertarianism by bankrolling university departments, think tanks, and like-minded local candidates. Now, after six years as two of the biggest moneymen in national politics, they’re starting to appreciate the virtues of their old model.

Their participation in federal elections has cost them millions of dollars and generated innumerable pieces of bad press. And for what? Sure, they helped engineer big Republican victories in the 2010 and 2014 midterms. But America is no closer to being Ayn Rand’s utopia — heck, the GOP Congress just reauthorized (the bastion of cronyism called) the Export-Import Bank.

And the Kochs’ long-term project — defeating big-government liberalism in the war of ideas — appears to be in dire shape. Per the National Review:

Koch allies say the brothers took tremendous interest in Bernie Sanders’ unlikely success — particularly his resonance with young voters who represent the future of the electorate — and drew stark conclusions about their own efforts. “Dumping hundreds of millions of dollars into elections doesn’t persuade enough people to achieve lasting change,” one Koch confidante says. “To achieve lasting change, the effort has to begin much earlier.”

You can’t indoctrinate the young with a 30-second ad — but you can generate ill will from potential corporate clients. These sad facts may reshape the Kochs’ political strategy for cycles to come.