One might be wrong. Or mistaken.
There are, after all, unknowns. And the unknowable. An honest person admits to their existence.
The left is certainly filled with "intolerant self-righteous moral certitude." But they are also wrong.
Belief in The Great Pumpkin might constitute a sincere belief system. But it is also wrong.
Sorry -- you're not making any logical sense. You're both criticizing AND invoking authority? You're doing the same thing that the author of the article was doing -- which was attempting to preach one thing, while asserting its opposite.
You can't critique someone on the basis of their "moral certainty," while being "morally certain" about it. I deal in logic -- and there's something wrong there.
Believe me, it takes a long time -- and a lot of psychological work to be able to truly accept the freedom of men.
And each side can believe the other is wrong until the cows come home, but neither has the license to limit their Constitutional rights, as a result.