Voting: Can a third party vote be justified?

To be completely honest, I am not at all excited about either of the candidates in the upcoming presidential election, and I am generally jaded by and disappointed in both the Republicans and the Democrats.

If I had to vote now I would probably vote for a third party candidate. When I mention this, most persons kind up turn of their nose and mention something about wasting the vote. My response varies from a shrug to something like the following...

In voting for a third party candidate I may be voting for someone who has no reasonable chance of winning. However, I am honestly placing my vote for the person whom I believe in. I feel like our 2-party system forces us into a false dichotomy. I don't feel like my interests are represented by either of the parties. Maybe, if enough of us express similar feelings on the current political climate, some change could take place. I'm not sure.

At least, that was by general thoughts, but now... I'm not so sure.

About a week ago I read a post on Vox-Nova by Henry Karlson entitled, In The Real World, We Can’t Get Away From Evil. He gave the example of Saints, like our own patron St. Thomas More, who cooperated with regimes committing evil deeds while refusing to directly participate in evil in the hopes of bringing about the greater long-term good.

I am attempting to discern the juxtaposition of voting for the person whom I believe is best vs. voting for someone who participate in evils but who may also bring about a better situation than the other primary candidate.

I encourage you to read the entire article. But even if you don't...what are you thoughts?