I vote third party because I vote for real change. If the people want change, they will have to vote for someone besides the big 2.
If you go to a restaurant R, and the service is lousy, do you go back? Some people do.
You get tired of the lousy service at restaurant R, so you decide to try restaurant D. Its the same terrible service.
Do I go to restaurant L to try and get restaurants R & D to change? No, I go to restaurant L because I like the service I go there.
There is a local mexican restaurant that I go to maybe 2 times a year - and they are terrible every time. So I go to the restaurant that provides good food and service.
The restaurant comparison is the way I look at political parties. The big 2 have not upheld their political promises, so I can not vote for them.
You are definitely missing the point.
Say you love the service at restaurant L, you think the service at restaurant R is bad, and you totally hate restaurant D. This is probably a fair representation, as the libertarian party and the Republicans have more in common at this point than the L's and Democrats.
What that means is that a fair portion of Libertarian votes are from people who would have voted Republican otherwise. (some others wouldn't have voted at all I'm sure) Say you have a district where the Republicans would have won 55-45 over the Democrats. If the Libertarians take enough Republican votes away, maybe you end up with a 45% Democrat, 40% Republican, 15% Libertarian split... and the Democrat wins.
So perversely by voting for the party that represents you best, you end up being governed by the party that represents you the worst. This is why winner take all, first past the post systems rationally trend towards being 2 party systems. Perhaps some people hate both parties exactly equally and so this doesn't matter, but that represents a very small percentage of voters. Almost all of them have a preference, and that's why third parties will never arise. (or if one does it will swiftly be co-opted by one of the big 2 or it will replace one)
