Perhaps the greatest number of them are so crippled by it, they aren't. They're either impoverished or imprisoned, but you have a few who become cult leaders, because their delusions follow themes that resonate or are shared by others who are merely delusional. Moreover, the leader's willingness to a lie to get people to believe his or her delusions would play on followers' hopes and fears. A cult leader of this sort grasps that the followers aren't as privileged to share his or her special insights. So, the leader is willing to tell the "white lie" in order to spread "greater truth." However, they may be so inclined to lie that they might do it when there's no calculation involved.
(I want to say that what I write next is hypothetical. It's the way I see Andrea Dworkin and other feminist leaders who seem to have left reality, and the original purpose of their movement, behind. I have no psychology degree, but I do have direct experience.)
This David Koresh "leader" is a bit different than his merely delusional followers, who will spread the lies the leader tells them, but won't originate any themselves. These would tend to be middle-rank followers, they tend to be sincere and unshakeable in their beliefs. They are not to be confused with the general membership. This last category doesn't have a mental illness besides any that may be caused by the cult.
A psychotic-psychopath may lead a secular movement. There's no psychological rule that says the pathological dynamic this personality creates only occurs in religions. I think totalitarian parties of the 20th century had it. Any somewhat fringe, borderline organization, such as the militia movement, or a conspiracy cult would be susceptible to it. I'm not saying it happens to them all the time, I'm saying when it occurs, it's most likely to happen with those organizations.
Therefore, you'll have someone like Andrea Dworkin in feminism. Unfortunately, I think there are likely others like her who have gravitated toward the women's movement and tend to spread false information within it. A lot of them in academia.
I've already pissed off women reading this, but I'll add: the whole feminist movement is not like this, thankfully, but it doesn't take very many to sidetrack it or even some damage. All it takes is a system that somehow promotes them leadership, or at least, makes them prestigious. I think feminists reliance on novel social science with no effective skepticism does just that.
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