(Andy Manis/Associated Press)

I’d thought the Koch brothers had merely funded Cato, but it turns out the libertarian think tank was in fact co-founded by Charles Koch in 1977 (for a pretty exhaustive list of Koch family connections, head here). But so what? The Koch brothers are major donors to an array of conservative causes, and for various reasons, they’ve become more celebrated than, say, the Coors family or the National Federation of Independent Business. But in much the way that conservatives became unusually and incorrectly obsessed with George Soros between 2004 and 2008, I worry that a lot of liberals have become overly fixated on the influence and power of the Koch brothers.

They’ve been helped along in this by conservatives who insist that the Koch brothers aren’t influential in conservative circles or spend their time promoting laxer drug laws or aren’t interested in aligning the conservative movement and their bottom line. These arguments are so transparently weak that they almost make it seem as if there’s something to hide. But as far as I can tell, the Koch brothers are rich ideologues/industrialists who are in competition with other rich ideologues, trade organizations, interest groups, constituents, activists, electoral incentives and so on to set the agenda of the Republican Party. Sometimes they are part of the coalition that succeeds, as in the case of energy policy. Sometimes they are part of the coalition that fails, as in the case of foreign policy. In the end, they’re probably more important than the Coors family but vastly less important than the Chamber of Commerce.

I’ve gotten a lot of e-mails, however, that present them as much more than that: Plenty of people seem to think, for instance, that Scott Walker took the call from a faux-Koch because he was working on his behalf, rather than because he wanted to use Koch’s money to advance his preexisting agenda. I think this gets the causality basically backward.

There’s an impulse on both sides of the political divide to attribute losses and unhelpful shifts in political opinion to shadowy, all-powerful organizations and financiers. Conservatives did it with ACORN; in fact, a recent poll showed that 25 percent of Republicans think ACORN, which no longer exists, might steal the 2012 election. After 2004, liberals became obsessed with James Dobson’s ministry — which made a bit more sense, given Dobson’s numbers, but still overstated the organization’s influence. Notice how rarely you hear about Dobson today.

The fixation on the Koch brothers is undoubtedly good for organizing — there’s a leadership vacuum in the Republican Party, which means organizers need to create foils. It’s also arguably healthy for rich guys who want to buy up the political system to face some risk of public backlash. And insofar as the Koch brothers are a symbol of the way that self-interested corporate money drives and distorts the Republican Party’s views on markets, that’s a useful dynamic to point out. But when it gets taken too far — when the Koch brothers and other players become overly causal in the way people view politics — that sort of analysis can lead to consequential errors.

On the left, for instance, the theory that Republicans were extremely responsive to the health-care industry was part of what led to the Obama administration’s effort to secure the support or neutrality of every major health-related interest group. Similarly, their sense that the Chamber of Commerce and other business groups could drive Republicans was important while they were constructing the stimulus. As it happened, they largely succeeded on winning industry neutrality both times, but that meant they ended up giving away a lot of good policy away in return for corporate support that led to approximately no Republican votes.

If they’d had a more realistic understanding of the Republican Party as an organization that was driven by a desire to win the next election and would thus oppose whatever Democrats offered, the policy might have ended up being better and the political strategy might have been more effective. In general, the Koch brothers are in a similar category: Influential political players court them for their money, work with them when it suits their purposes and ignore them otherwise. That makes them a lot more powerful than you or me, and certainly worthy of attention. But it doesn’t make them into a grand unified theory of conservative politics,and people should be skeptical when they’re presented as such.