What happens when the lone voice is in the right, and the mass of people are in the wrong, and all of the preponderance of current science and wisdom is against the lone voice? It's no great stretch to find examples through history of this in different social contexts.
Not to get nakedly political, but for someone who became old enough to start being aware of politics in the early 2000s, it was pretty easy to look at the GWB and Obama administrations and fall into the narrative of "oh, our side are clearly the good guys" as a kid and early in college (as I think most kids do). The last few years have made it clear to me that this amoral, either-with-me-or-my-enemy approach to politics is pretty independent of where you lie on the political spectrum. Every part of the spectrum has its shitty people and unfortunately we're in a cycle where those people are the ones dominating the discourse everywhere you look.
There's a reason wars of religion and ideology are always the bloodiest. If it's 1600s Europe and you're a soldier in a war of conquest, it's a lot easier to see the enemy soldiers and civilians as just trying to get by in the world buffeted by the same forces you are. On the other hand, if their entire existence and belief system are an affront to God, it was a hell of a lot easier for the worst and most bloodthirsty parts of the human psyche to kick in. The social technologies we've developed to handle pluralism nonviolently have been incredibly successful by the standards of most of human history. I guess all it takes is enough stupid, myopic, and/or amoral people to sacrifice the stability they engender for short-term political gain.
I see the same thing playing out (in much less dramatic fashion) among many of my nominally compassionate, kind-hearted friends. The other side isn't considered misguided, or to have a different understanding of the world (or heaven forbid, possibly more correct than you): they're just evil. Every dirty rhetorical trick to twist their words is fair game, and attempts from decent people to even point out that the other side is being misrepresented is giving aid and comfort to the enemy.
It happened just this weekend: my friend mocked one of the points the essay author made, and when I pointed out that he was misrepresenting (or misunderstanding) it, his response was something like "I don't think men are the ones who need help in the world at this point in time". There's no such thing as truth or honesty to most people, just "how can I spin this to support what I already know the answer _should_ be"