The libertarian distaste for politics and voting guarantees that they will remain without influence -- a good thing from my point of view, but probably not yours.Voting is a ritual of social participation. The point of voting is not (as Landsberg stupidly holds) that it is only worth doing if you stand a chance of casting the single vote that tips the balance past 50/50. The point is that you are joining in with other members of your community to make a collective decision. The act of voting is a humbling and equalizing one -- in voting you (briefly) set aside your personal identity and personal power and act as just another equal citizen among others, willing to take the economic hit for the benefit of playing their small part in the collective political ritual.
Here are some of my thoughts on voting from a couple of years ago, see especially the link to the Valdis Krebs paper.
The Landsberg piece you link to is a typically autistic piece of economist crapola. The Freakonomics boys made the same argument and I answered them there (first comment).
I think there's an interesting comparison to be made between voting as a ritual and religious rituals, in fact. The point of religious rituals is in their collective enactment. They don't "do" anything except foster a sense of solidarity amongst their participants. But this is not at all trivial. Voting may play the same role, with the endpoint decision being less important than the ritual, and the jealously fought-for rights to participate in it.
Libertarians have a problem with this. Either they can't understand it at all, or they equate it with North Korea's mass rallies. Or they feel threatened by it. I suspect that what's going on in many libertarians is that their sense of individual identity is so weak that it feels existentially threatened by acknowledging the social nature of human existence. The Ayn Randroids are the most notable in this regard.