In his cover story for the new issue of National Review, “Conservatives on the Couch” (not yet available online), Ramesh Ponnuru devotes considerable ink to debunking the recent Cato study by David Boaz and David Kirby on “The Libertarian Vote.” I think he misses the point.

Here’s Ramesh:

David Boaz and David Kirby … have recently made an ambitious attempt to claim that libertarians are the swing voters at the center of American politics. Their chief evidence: The 15 percent of voters whom they identify as broadly “libertarian” gave Bush 72 percent of their votes in 2000 and only 59 percent in 2004….

They seem unaware that their data tell more against than for their thesis. The electorate as a whole swung toward Bush during those years: He increased his percentage of the overall vote from 48 to 51. Libertarians swung one way; the remaining 85 percent of the electorate swung the other way, and swung far enough to overwhelm the libertarians. Could it be that the same actions that alienated libertarians won Bush the support of these other voters? Well, yes, it could.

For those keeping score at home, here’s how my card reads: Ramesh, 1; Straw Man, 0!

Ramesh does a fine job of marshaling evidence in support of the utterly obvious. Of course libertarians aren’t the kingmakers of American politics. Of course it’s possible to ignore particular libertarian concerns and profit electorally. If those things weren’t true, much of American history would be inexplicable.

As I read it anyway, “The Libertarian Vote” makes more modest claims than those Ramesh seeks to refute. And Ramesh’s critique leaves those modest but important claims intact.

The fact is we don’t know why libertarian support for Bush declined between 2000 and 2004. Was it the war? Big spending? Social issues? The overall stink of incompetence? Or some or all of the above? We just don’t know.

We therefore don’t know what overlap there is between the issues that underlay reduced libertarian support and those that underlay increased overall support. It’s possible that an alternative-universe Bush administration could have taken positions that maintained or increased libertarian support while increasing support from other quarters as well – thus producing an even bigger victory in 2004 than the one that occurred here (which was pretty anemic for an incumbent with an expanding economy).

Here’s what we do know after reading “The Libertarian Vote.” The group of broadly libertarian, “economically conservative but socially liberal” voters makes up around 15 percent of the population. Historically, these voters have strongly favored Republicans, but their level of support fluctuates and has been trending down of late.

And what does that mean? It means that Democrats might be able to capitalize on those recent trends if they made any concerted effort at all to appeal to libertarians. And by so capitalizing, they might be able to change the outcome of close elections.

And if Democrats started winning by attracting libertarians who used to vote GOP – as it appears they have begun doing in Western states, according to Ryan Sager – libertarians could actually end up as a bona fide swing constituency, actively courted by both sides. And wouldn’t that be fun?

We’re not there yet. Right now, the libertarian vote is only a potentially important swing constituency. It has come into play for reasons we don’t understand well. But it’s big enough, and volatile enough, that it could lend decisive aid to either party that courts it.

Ramesh’s message seems to be that small-government types are unpopular nerds who should content themselves with being allowed to run with the social-conservative cool kids. (Yeah, I know that sounds funny – the conservative cool kids, I mean, not the libertarian nerds.)

I say libertarians can do better than that. And the data in “The Libertarian Vote” show that isn’t just an idle fantasy.