...the Kochs will happily put their money behind candidates and intellectuals who agree with their economic agenda but disagree with their social agenda. They will never put their money behind candidates or intellectuals of whom the reverse is true.
In the same post, Chait runs off a series of sums the Kochs have spent over the years on various right-wing causes. Curiously missing, however, is the $20 million donation the Kochs made to the ACLU to fight the Bush administration over the PATRIOT Act. Browsing various accounts of the Kochs political spending over the years, that $20 million appears to be substantially more than the Kochs have contributed to all political candidates combined for at least the last 15 years. (Their gifts to the arts and other non-political charities exceeds what they've spent on politics many times over.)
Now maybe we shouldn't fault Chait for overlooking the ACLU donation. The Kochs don't appear to have gone out of their way to publicize it. (Though, curiously, when they don't publicize their contributions to free market causes, it tends to be interpreted as stealthy or manipulative.) It's also not nearly as prominently reported on the web as the gifts they've made to free market organizations. There's another mention on the Faces of Philanthropy site, which appears to be down right now. But here's a cached version. I suspect the mere possibility that the Kochs could make such a gift didn't enter the minds of most people who have written about all of this. It wasn't mentioned in Jane Mayer's much-hyped New Yorker expose, either. I should note that both the linked sources above are secondhand, and I'm waiting to hear back from the ACLU for confirmation.
The Kochs' contributions to political candidates are often touted as the true indicator of what the family and their company really stand for. I'm not particularly fond of most of the politicians the Kochs have supported over the years, but it seems to me that this is precisely backwards. It's not only significant that the Kochs' contributions to actual politicians are dwarfed by gifts like the one they made to the ACLU, their spending to found and fund think tanks, and their contributions to non-political causes like the arts and medical research—this is precisely the point.
Yes, like most corporations, the Kochs spend money on the political process to protect their interests, sometimes on unlibertarian politicians and unlibertarian causes. Sure, go ahead and criticize them for that. But though I've never met either of the Koch brothers, I suspect that like most libertarians, they'd rather avoid the unseemly world of politics as often as possible, where winning generally means forcing other people to bend to your will. (David Koch did run for Vice President on the Libertarian Party ticket in 1980, but on a platform of legalizing drugs and prostitution, and abolishing the FBI and CIA.) They seem more interested in contributing to voluntary, civil society, by promoting ideas (yes, through think tanks and magazines like Reason), the arts, research, and by fighting particularly pernicious laws like the PATRIOT Act through the courts instead of through contributions to generally spineless politicians. (That latter strategy appears to have been the correct one—the courts have done far more to restrict executive power in the war on terror than Congress has.)
This approach is certainly reflected in their giving patterns. It's true, when you strip away all their giving that didn't go to political candidates, as Chait does, the Kochs look fairly right-wing. But you've also just stripped away the vast, vast majority of Koch giving. The more complete picture is pretty doctrinaire libertarian, with support not just for civil liberties, but donations to promote civil society in general.
UPDATE: Reason was unable to obtain official confirmation of the donation.