No offense to Jane Steen and the Green Party, but while her specific goals and policies may vary, she's running as Pretty Much a Democrat. If she has to stand outside the building and try to siphon off Bernie supporters because she can't make it inside the convention hall full of people that largely agree with her on many issues, what is she going to do when she has to face an opposition party that doesn't agree with her ideas, or a foreign nation that is hostile to them? Same goes for Atlas Shrugged on the Libertarians ticket on the right. Voting for a third party isn't just a problem because they won't win, it's also the fact that they'd probably be a pretty crappy President.
This election, more than most, has shown how elastic the two major parties can be in terms of where they end up on their side of the spectrum. There are lots of legit third party candidates that people always yearn for, they just lose out in the primaries. If you don't like the final two options available because they don't match your views perfectly, tough luck. If you show up five minutes before dinner is on the table, you don't get much input in what is on the menu.
