Are we fanatics?

I seem to be on a binge of books that make me wonder. Today's book is Jon Krakauer's Under the Banner of Heaven: A Story of Violent Faith. This is a book I mentioned before in connection with my reflections on whether a religion can abandon founding tenets and still be considered true to itself.

Krakauer's book focuses on two breakaway polygamist Mormons who committed violent murder against their sister-in-law and her fifteen month old daughter. In tracking down the events that led to these killings, Krakauer tells, not only the murderers' story, but also the history of the Mormon church. And that history inevitably embraces those who now claim the banner of the original Mormon faith — something they do primarily by embracing polygamy. What characterizes so many of the fundamentalists he describes is that they started off as ordinary Mormons or non-Mormon Christians; they had various epiphanies that led them (they believed) to seminal truths; and they were convinced that, having learned these revealed truths, everyone who didn't embrace the truths was wrong or evil.

Well, folks, that could be me. I started life as an ordinary liberal Democrat (who always had conservative leanings); I had an epiphany in the wake of 9/11, when I decided the world had arrayed itself in an Us vs. Them pattern, and that those who deny this pattern are wrong; and I constantly hark back to a pure America of the Good War of the 1940s, and the (at least superficially) coherent society of the 1950s. I'm now sure enough of my newfound beliefs to blog about them regularly and to try to convince people, through my blog, to see the world as I see it. Certainly, my husband, who has remained true to his original Democratic faith, perceives me as having gone off the deep end.

So my question is: Have I gone off the deep end? Where does commitment end and fanaticism begin? When does a change of heart cease to be the reasoned development of the intellect and become the kind of blind faith that can lead one to commit dangerous or wrongful acts? Feedback anyone?

UPDATE:  Perhaps the self-restraint Dennis Prager discusses in this article (conservative vs. liberal self-restraint) is part of what separates the fanatics from those who are merely committed to a belief system.