After meeting several charismatics I tend to go towards to Aero and Jasmincar's assessment.
Very few of these people are unable or unwilling to abuse their power. Think JFK, with his public persona, vs his private.
They make great conmen/women are usually extremely sexually attractive, to the opposite sex.
I was quite shocked both at the time and afterwards when I met a pair of right wing politicians, at a gun show. They were a couple at the time. Impeccable dress sense and manicuring. Despite my rational mind telling me otherwise, I felt like I was in the presence of higher beings. Otherworldly magnitude like Frodo in the presence of Galadriel. I felt blessed that they deigned to talk to me.
In time, in the media they both turned out to be pretty untrustworthy, unlikeable individuals and either their interest in politics waned, or they lost popularity with their core supporters and they disappeared back into anonymity.
If you can get a bit a distance, when the irrational feelings start its easy enough to see they are "all show and no go". Mainly image, with a conman underneath, tapping into something primal, and trying to manipulate you.
That being said its not always bad I remember being in a cafe with my then girlfriend. There was a group of really good looking women, I thought models. Even though I would have said all the other women in the group were beautiful this one seemed to radiate an aura, and seemed a magnitude, head and shoulders above the others or indeed any one else I had seen in my entire life. I was probably drooling, my girlfriend said something
like "It's alright, I don't mind you looking at her, I can't stop looking at her and so is everyone else in the room".