Safety to breed? Kind of.* I think you're all missing the obvious...

The template of the charismatic person is the idealist thinker who wants something better for mankind. Think Yuri Zhivago. (Lenin.) Hitler. They're not tricking us: we have the ability to recognize that they really believe in their ideas, and that they are willing to sacrifice all that is necessary to realize those ideas. Our trust in their ability to realize their ideas may be misplaced, and of course our trust in their ideas may be misplaced.

The "spell" though is the ideas they represent. If you want to explain why we follow, you just need to explain our idealistic tendencies; our ability at times to sacrifice our time, money, even our lives and all our other values for an idea. A charismatic person is someone who is able to stir up our innate idealism in the direction of their chosen ideals.

*Idealistically, I can think of the most idealistic leaders as the altruists willing to sacrifice their lives for the cause while the masses are busy raising their families...