WHY I'M NOT A LIBERTARIAN (EXACTLY): I like libertarian ideas in some respects -- I believe that the government which governs least also governs best. The point of government is to prevent people from interfering with my life, and to leave me alone. That's pretty much it.
So why aren't I a Libertarian? Well, most Libertarians' foreign policy is far too isolationist for my tastes. I believe that one of the only essential mandates for government is to protect me, and in order to do that it may sometimes be necessary to have an active foreign policy (such as with Iraq and Afghanistan).
I tend to be more socially conservative than most libertarians... not because I want the government to meddle in my private life, but because, for instance, I consider abortion to be murder. Most Libertarians are pro-choice, but if they believed that abortion was murder they probably wouldn't be. I'm also not sure that legalizing drugs will solve as many problems as most Libertarians do, and I see some value in having laws that restrict freedom in order to prevent activities that have a very high likelyhood of causing damage or injury.
For instance, many Libertarians I know are against drunk driving laws, on the grounds that it's already illegal to run someone over with your car -- they think there's no reason to punish someone unless they
actually hit someone. In my mind, this is like saying that it shouldn't be illegal to fire a gun into a crowd of people; we've already got laws against shooting another person, but if you don't hit anyone then what's the problem?
Libertarian ideas are nice, in theory, but in reality I don't think they completely pan out. There is a great advantage to social order and central government or else it wouldn't exist; the trick is in finding a balance of power between the group and the individual. I do think that in some ways our government has too much power, but most of my complaints could be solved by drastic tax cuts that left other laws untouched. That said, I'm very grateful to all the brilliant Libertarians out there who are fighting the good fight against excessive government, and more often than not I'm right there with you.
Update:
Amazingly,
Mark Aveyard has just posted a rather elegant fisking of pro-choice Libertarian Arthur Silbur. What excellent timing! You'd almost think we planned it.
Update 2:
I want to briefly clarify my stance on abortion. Abortion is
killing a human being, but in some cases killing is not
murder.