(This was in response to a column by the newspaper's owner- click on the picture to read it- which suggested that the presence of a Libertarian candidate ensured the victory of the Democrat in the VA governor's race. I was asked to weigh in on the matter from a libertarian perspective.)
First of all, I am what you would call a "small 'l' libertarian" as opposed to a "Big 'L' Libertarian". It's the difference between being a philosophical libertarian and being a political libertarian (a member of the Libertarian Party). They can be the same, but often aren't.
The Libertarian Party is a political party supposedly based upon the principles of libertarianism- but they often fall short due to their desire to win elections- or to at least play the game. They soft peddle and avoid topics they think would hurt them, and because of that can't even get the support of many libertarians. I used to be a dues-paying member of the Libertarian Party, but dropped out because of the LP's refusal to stick to the principles.
When they lose an election, both Republicans and Democrats think Libertarians took votes from them. Both are probably correct to a degree, depending on the particular election, but I think in most cases the people who end up voting for the Libertarian candidate simply wouldn't have voted at all if there hadn't been a Libertarian on the ballot. There is a simple solution- become more libertarian rather than constantly whining that libertarians should vote for candidates they find repugnant.
Most Libertarians, and practically all libertarians, see no reason to prefer the Republican candidate over the Democrat, or vice versa. Most see them both as simply different branches of the same political party, rather than seeing the superficial differences they emphasize having any actual value at all. If you are being chased by a hungry tiger, why would you care what color the stripes on his tail are? Both Democrats and Republicans believe it's their "right" to control what you do with your own life and property, and will use deadly force to enforce compliance. The only difference is in which parts of your life and property they choose to interfere with. That's no choice.
One big part of libertarian (and principled Libertarian) thinking is that a vote for the lesser of two evils just keeps resulting in more evil. If the choice is between two people who shouldn't be holding office, then to vote for either one is endorsing someone you don't want under the belief that "you have to vote for someone". No, you don't. It's better to not participate than to throw your support behind someone you know is dangerous to individual liberty. If you vote you are implicitly agreeing to go along with the result even if "your side" loses. In other words, if you vote you have no right to complain about the results. Yes, I know the voters usually turn that upside down, but think about it: If you play chess by the rules, how can you complain if you lose? Especially if you keep agreeing to play chess with a known cheat, or with someone who keeps changing the rules mid-game to favor himself. In that case the only winning move is to refuse to be drawn in. Go play something else instead.