I assume you've read it. But for other readers of this thread, Eric Hoffer's book The True Believer: https://en.wikipedia.org/wiki/The_True_Believer https://en.

I assume you've read it. But for other readers of this thread, Eric Hoffer's book The True Believer: https://en.wikipedia.org/wiki/The_True_Believer https://en.wikipedia.org/wiki/The_True_Believer Is a great exploration of educated people becoming extremists. It's an easy read and the literal origin of the phrase 'True Believer' in modern English