I'm glad you asked.

In our current system, the presence of third party candidates on a ballot lead to a spoiler effect. For example: if there is a major party and a minor third party that have similar ideological views and there is another major party with no ideologically similar third party running, even though one ideology may get the most votes, the major party without a spoiler will win. An example of this was the Mannix/Kulongoski election. There was a candidate by the name of...Tom Cox? I think it was who was running as libertarian. If you recall, that election was very close. The combined votes of Mannix and Cox outweighed the Democratic candidate, but unity on the liberal side allowed the win.

This isn't so much a criticism of third parties, but rather a criticism of our electoral process. What we have in this country is known as "First Past the Post" elections. This means that whoever gets the most votes, despite not being a majority, will win. On the surface, this seems like a reasonable and very democratic solution to government, but the truth is that it can lead to people being governed by someone only a minority wanted. How often have you heard someone say that, "A vote for third party candidate X is just throwing your vote away!" This is a symptom of our first past the post problem.

A better system is an alternate vote. This means that you list the candidates in order of preference, and then the votes are tallied. Whoever receives the fewest votes has all their ballots essentially cast aside. Those ballots then have their next choices looked at and those votes are moved to the appropriate candidates. This continues until there are only two candidates left and one has a clear majority.

The result of moving to an alternate vote would be three-fold.

Firstly, it would remove the penalty of voting for a third party candidate by making it so your vote is not thrown away.

Secondly, whoever wins the election will have more people voting for them rather than against the other guy, thus leading to a populace governed by someone they like

Thirdly, it would allow third parties to grow more of a base. The benefit of this is it would lead to a larger, less polarized, discussion of issues that affect us and hopefully will lead to better solutions.

So, I don't really dislike third parties, but I dislike their role in our current electoral system.

As far as the green party, I think they're a little crazy and add nothing positive, which is why I did not give a single...pheasant regarding their potential demise.