I tend to side with the Libertarian party on many issues, and almost always vote for Libertarian candidates when they are running against a Republican who does not have a Democrat opponent.
But no way, no how am I wasting my vote on a Libertarian candidate who has no shot to win, who has not been thoroughly vetted, and is often unqualified for the position for which they are running.
Via the Wall Street Journal:
As a young libertarian, I was very enthusiastic about the formation of the Libertarian Party. I proudly cast my vote for Roger MacBride for president. I attended the 1975 national convention in New York that nominated him. But, while I am as libertarian today as I was then, I have come to believe that the Libertarian Party was a mistake.
The reason is simple. Unlike a parliamentary system in which governments are formed by coalitions of large and small parties, our electoral system is a first-past-the-post, winner-take-all one in which a winning presidential candidate just needs to get more than 50% of the vote. This means each contending “major” party is itself a coalition that needs to assemble enough diverse voting groups within it to get to 51%. Hence the need to appeal to the so-called moderates and independents rather than the more “extreme” elements within.
To the extent that a third party is successful, it will drain votes from the coalition party to which it is closest and help elect the coalition party that is further removed from its interests. The Libertarian Party’s effort will, if effective, attract more libertarian voters away from the candidate who is marginally less hostile to liberty, and help hand the election to the candidate who is more hostile to liberty.
Fortunately, because this drawback is so obvious, the Libertarian Party’s presidential vote has remained minuscule. (It was about 0.4% in 2008, though it could cost Mitt Romney the electoral votes of New Hampshire this time around). Most libertarian voters resist the party’s call, even when, as this year, it has nominated a good man like Gary Johnson, the former governor of New Mexico.