Vox nails it...

Where was the unprecedented turnout? Where was this giant swell of voters, drawn to the Hope/Change love bus? It didn't show up, turns out.

Yes, I voted Libertarian. No, I didn't make a difference. It's just a ritual I go through. As usual, Vox Day hammers it out of the park.

...Voting these days primarily concerns how the spoils of government revenue will be divided, an act of little interest to the libertarian.

As Nate has pointed out in the past, it is almost impossible to think of a single historical situation where freedom from government control has come about through the peaceful means of voting. (By all means, do feel free to propose any examples in the comments.) Men have voted away their liberties since Gaius Marius was first elected to an unprecedented third term as consul, but they seldom seem to ever see fit to vote themselves more freedom.

And that my friends, is why so many are apathetic. You don't change the system from within. It doesn't work. You can try, and I will think you noble. But it doesn't work.