[T]he community of the left is a community of meaning, and is bound by ties that are fundamentally religious. For the non-religious, politics is the art of managing the possible. For the left, it is the path to social and personal redemption. This messianism is the left's political essence. For the left, politics is ultimately not about practical options on which reasonable people may reasonably differ. It is about moral choices that define one as human. It is about taking sides in a war that will decide the future of mankind and about whether principles like "social justice" will prevail. It is about us being on the side of the angels, and them as the party of the damned.
(David Horowitz, The Black Book of the American Left: The Collected Conservative Writings of David Horowitz, vol. II, Progressives [Los Angeles: Second Thoughts Books, 2013], 159 [italics in original])
Note from KBJ: This explains why people who go from progressivism to conservatism (like Horowitz and yours truly) are excommunicated (with great fanfare) from the progressive church. These apostates (as the Left sees them) have indicated by their choice(s) that they no longer adhere to the correct religion. They've gone over to the dark side. And what is worse, they threaten to "tell all" about what went on inside the church. I know more about progressivism than most progressives do. They know that I know this; they hate that I know this; and they do everything they can to silence me so that I can't or won't divulge it. I divulge it. Thank god I live in a place, and at a time, where I may speak the truth as I see it. There are times at which (and places in which) I would have been killed, imprisoned, or institutionalized for my heresy. I should say a word of thanks, too, for the institution of academic tenure, which allows me to move freely about the premises of the progressive church, making observations, striking up conversations, and seeing to it that the indoctrination of students into the progressive faith is less than complete.