As Gene noted earlier, Markos "Kos" Moulitsas has put up an interesting big-think post over at DailyKos advancing the ideals of the "Libertarian Democrat," about which, apparently, he is writing a book. Kos rightly points out that libertarians have very little in common with the GOP in its present incarnation. So what is to prevent libertarians from siding with the Democrats in elections? Before I delve into Kos's answer, let me say what I think is the major barrier to a left/libertarian lovefest.

There is some evidence that personality traits predict party affiliation. For example, "openness to experience," one of the "big five" personality traits, strongly correlates with ideological preference. According to psychologist Robert R. McCrae:

Open individuals have an affinity for liberal, progressive, left-wing political views, whereas closed individuals prefer conservative, traditional, right wing views. Indeed, a case can be made for saying that variations in experiential openness are the major psychological determinant of political polarities. [Paper abstract.]

Now, the following is far from rigorously scientific, but I think it's pretty indicative. I have a talk on the psychology of persuasion that I've given to a number of libertarian groups. I've been giving out a short "openness to experience" quiz at the beginning (inspired by this fascinating presentation [ppt] by UVA psychologist Jonathan Haidt. ) The results? People who self-select to attend a libertarian talk about persuasion score extremely high on "openness to experience," which predicts an audience with socially liberal preferences and largely Democratic party affiliation. But almost none of these people vote for Democrats. Why not?

Insofar as political commitment isn't simply a matter of personality, or of reflexive adherence to what the people around you happen to believe, I think the barrier between liberals and libertarians has almost entirely to do with different answers to empirical questions about the way markets and governments function. The different syndromes of approving and disapproving sentiments about market and state characteristic of libertarians and welfare state liberals more or less follow upon these prior judgments of fact. Libertarians and liberals---classical liberals and welfare state liberals---are generally the same kind of people at the level of certain core aspects of personality that tend to influence political affiliation. The difference, then, is likely a function of the way different sets of beliefs mediate the expression of personality.

The thing that keeps me from throwing my lot in with Democrats has everything to do with their consistent underestimation of the efficacy and justice of institutions that make the most of the information carried by market prices, and their consistent overestimation of the efficacy and justice of bureaucratic political management. Love markets more, and love the state less, and libertarians may come a knockin'. A recent Pew survey reported that only 50 percent of the people they identify as libertarians either identify as or lean toward Republicans, while a healthy 43 percent identify as or already lean toward Democrats. Libertarians may be ripe for the pickin'.

Now, here's Kos:

The problem with this form [the usual form] of libertarianism is that it assumes that only two forces can infringe on liberty -- the government and other individuals.

The Libertarian Democrat understands that there is a third danger to personal liberty -- the corporation. The Libertarian Dem understands that corporations, left unchecked, can be huge dangers to our personal liberties.

I think Kos underestimates just how wary of corporations libertarians generally are. Classical liberal political economy tells us that the greater the scope and power of state coercion, the stronger the incentive for economically powerful private interests, such as corporations, to use it to their own advantage, squashing competition, consolidating advantage, and channeling taxpayer dollars into corporate coffers. Libertarians have never believed in leaving corporations unchecked. The way you check corporations is by taking political power off the table.

Here is Kos' key paragraph, which contains the real division between classical and statist liberals:

It's pretty clear that Kos is pushing a program of positive liberty rather in opposition to the classical libertarian notion of liberty as non-interference. I fear that once you cash out precisely what Kos has in mind by ensuring that people aren't "unduly exploited by employers," whatever that means, or by "poverty prevention" and "social net programs," we'll discover something disappointingly like the Democratic party status quo. In which case, Kos will be simply declaring a pretty standard set of Democratic policies as "libertarian," in defiance of the normal understanding of the term. Is this a Machiavellian attempt at the dark Lakovian arts of re-framing? Or, more hopefully, a reflection of a sincere wish to court libertarians away from a lately abusive alliance with Republicans?

If it is the latter, then simply recognizing that the 2nd Amendment is in fact part of the US Constitution and using the word 'libertarian,' is not going to much help Kos' cause. As Gene did, it really is worth pointing out common ground between libertarians and the left. Nobel-winning libertarian heroes such as Friedrich Hayek and Milton Friedman have supported a tax-funded safety net, and so would I, if it was sanely designed. Now, if Democrats like Kos really meant it, and started thinking about market and government institutions in anything remotely like the way Friedman and Hayek were thinking when they proposed their minimum income policies, or started thinking about environmental policy like PERC, or threw away their silly vestigial Marxist model of agonistic employee-employer relationships — which is just to say, if Democrats actually become more recognizably libertarian— then I think the psychological evidence supports the hypothesis that personality-compatible libertarians would flock to the Democrats in droves.

But talk is cheap. So show me the libertarianism.