David Boaz writes, “Guess [Ponnuru] didn’t buy our argument that ‘Libertarians seem to be a lead indicator of trends in centrist, independent-minded voters,’ and they’re currently leading independents in a flight from the Obama agenda.” No, I didn’t buy it. As I wrote, Boaz and his co-author showed that libertarians soured on Bush-era Republicans before the larger public did (indeed, while the public was getting more pro-Republican) and then moved away from the Democrats before the larger public did (indeed, while the public was getting more pro-Democratic). But they provided nothing beyond assertion for their interpretation of this sequence.

They didn’t even posit a mechanism by which the movement of the libertarian fraction of the public would later move other, larger groups. The more I think about it, the less plausible their assertion seems.

Let’s consider that liberal/conservative/libertarian/populist typology I mentioned yesterday (the “populists” being social conservatives and economic liberals). I don’t have data on this point, but it seems fair to assume that people who are socially and economically liberal, or socially and economically conservative, are much less likely to move back and forth between parties than the more “mixed” two groups. To see my point, assume oversimply that the “consistent” groups don’t swing at all. The libertarian and populist groups are roughly equal in size, each about a fifth of the electorate. If they’re the only two groups swinging, libertarians have swung one way, and the public as a whole has swung the other, it follows, doesn’t it, that the populists have swung more than the libertarians?

But if that’s the case, it undermines the whole point of the “libertarian vote” project: to establish the libertarian vote as a group that makes sense for self-interested political parties to court. For it means that the parties are better off courting the much more malleable group of voters whose policy views are exactly the reverse of the libertarians. And it also creates a problem with the libertarian leadership storyline: Why would the movement of libertarians cause anti-libertarians to move in the exact same direction, but with a time delay?