No American here. I ask myself, does a third candidate have any real chance of getting enough votes to gain visibility in the media and elsewhere? Even if it is for future elections?
I don't know the answer, but if it's no and you know it and still decide to vote for a third candidate, you're an idiot. Work to make this a reality within four years, for the next four years, if you don't do it and just complain you're an asshole.