I get it. You don’t like Hillary. She’s a little too progressive for some Trump hating Republicans to bear. And Gary Johnson is just such a cool guy. He rock climbs and speaks like that cool uncle (not the uncle that tried to be cool but always came off as weird and sometimes even pervish, the actually cool one). Sure, he had that little Aleppo flub, but he’s the guy that’s closest to your political views.
But here’s the thing: as much as you would like to believe otherwise, this is not a three way, or (sorry Jill Stein fan) even a four way race. Johnson, according to polling aggregates by FiveThirtyEight as of September 26th, has a 2.7% chance of winning at least one electoral vote (out of a 270 electoral votes needed to win). Since he already missed the cut off to qualify for the debates, that chance is not going to change any time soon.
This is because the current system heavily favors a two party system, as every state but Maine and Nebraska (each with just two electoral votes) has a winner takes all rule in place.
That means that the candidate with the most votes in New York takes all 29 electoral votes, even if they win by just a small margin. So while Johnson might have 8.5% of the popular vote, he does not have the support to win a plurality in any state. It takes resources and a base of support that third party candidates lack to achieve a plurality in any state, which is why the last third party candidate to win even one electoral vote was George Wallace in 1968.
Whether you like it or not, this is a race between Hillary and Donald. Pick which one you dislike the least (it should not be too difficult) and vote for them come November.
If Trump wins, and you voted Johnson, you share as much of the blame as every single Trump voter out there. You refused to pick a side, and thus refused to prevent such an outcome from happening.
You might think that your “neutrality” bids you a clean conscience, but the fault in your logic comes with thinking that neutrality exists at all. There is no such thing as neutrality. In a binary situation where either Side A wins or Side B wins, there is no position that does not aid either side. If Side A is stronger and going to beat Side B, then by not supporting Side B or fighting Side A, you are in effect helping Side A to win and condemning Side B to lose. Inaction, indecisiveness, or “neutrality” in effect actually is supporting the more dominant side.
So if the side you don’t like who wins this election, your lack of voting against him or her, even if you did not vote for him or her, has helped them achieve this victory.
(PS: This applies to not voting for anyone as well.)