Why is almost everyone so blinded by charisma that nothing else matters?

This thought occurred to me when I was reading up on Michael Swango today. To me, charisma is as transparent as the windshield of a brand new car, and the ability to see through it has helped me and a few others here respond to some problematic members early in this site's history. If a person considered to be charismatic is dangerous, I recognize it right away. What is it about charisma that is so powerful that it literally lets some people get away with murder? I suspect that the ability to see through it is somehow connected to social ineptness, at least with me. I often wonder if I'll lose the ability if I ever become socially active.