It is the capitalist economy
Third parties generally serve only to take votes from one of the main parties. Third parties generally serve only to take votes from one of the main parties. If the third party has a candidate promising similar things to the Rep. candidate, the Democrats are more likely to win simply because their votes are not being siphoned off. Think of it this way: if a school class were to vote on favorite colors and there were only blue and red to choose from, it would probably be mostly equal. But if the same class were to vote for blue, teal, and red, I would be willing to bet that red would win just because its votes weren't being split like the blue votes were. Teal is the third party. It won't ever win on its own, but it can be influential in that it can help the opposite party win.
Probably leaving for food or religious reasons.
I believe the answer is: motivations.
When you understand your motivations, you would most likely wouldn't stop unless your end goal is achieved because you feel a strong drive for a certain change. Because of this, the likelihood of you staying within your plan would also be increased.
