It was a while ago, but a couple people asked me about my opinion of voting third party, so I thought I'd lay out what I think is the way to decide who you vote for. Of course, this is my opinion, I claim no 'eternal truth' to this one.
I have thought about this one a lot, particularly this election cycle. As I hear the claims that you 'have' to vote for one person or another, or it's your fault that someone wins, etc.. This is what I came up with. When a major election like this happens, I think the first hurdle is being qualified. Experience, previous positions or jobs held, education, intelligence, resume so to speak, etc.. I think someone can be a wonderful person and be uneducated, or have worked a blue collar type job, or any number of other things that the world or society may deem less successful. I don't believe those things speak to someone's inherent value, but I do think they speak to whether or not someone is qualified for certain jobs or positions. So, first step, is the candidate qualified. Now, at this level, it is rare that someone actually runs and is not qualified for the job, but it is possible. Ralph Nader, for instance, is someone I consider completely unqualified for the job. Once you pass the hurdle of being qualified, I think the next step is looking at any number of things that may override those qualifications. Demeanor, history, morality, ethics, etc.. This one does not require perfection. I believe we should try to find good men and women to vote for, but at the same time, we cannot demand perfection. There are things that people can do, in my opinion, that override their qualifications, for lack of a better term, I'll call that being overall qualified. To state the obvious, this variable is going to be different for different people. The hope is that people will base these off of facts as much as possible, and not just rumor.
If you have more than one candidate that after this calculus is 'overall qualified' then I think the candidates positions and their adherence to what you want to happen is a completely correct way to decide who to vote for. Personally, I don't think it is reasonable to vote for someone who agrees with your political stances, if they do not meet the standard of being overall qualified. Nor do I believe that it is reasonable to vote for someone who is not overall qualified even if the other guy is even less qualified (or to put it another way, if the opponent is more reprehensible). I don't think this only applies to the two main parties. To be clear, I kind of hate the two party system, and blame it for most of our current political problems. This blame, while directed at the two parties, really lies with us, because it is us who buys in to the system so much that we refuse to change it.
So, as to the question of voting for a third party candidate the final answer is this. I think it is right to vote for any candidate that is overall qualified. Whether they are one of the two major parties or not, I think it is a right choice for anyone to vote for anyone who is overall qualified. I may disagree with someone's decision on who is overall qualified, but like almost all things political the vast majority of those decisions are purely opinion based.