I agree with VAX (suprisingly).
Since charisma is used to modify the attitudes of people, and beauty modifies your attitude...
All other things being equal, the same 'pitch' from an attractive person is more successful than an unattractive one. You cannot turn to extremes, to justify an argument in this case. Both Hitler, and the annoying self centered model are extremes. Jus tthink about the last time an attractive person made a comment to you, and the impact it had, vs an unattractive person, amking the same comment, and the shift in impact.
I'm not sure how subjective standards of beauty are. I'll provide a counter example to the eskimo.
How many times have you been to a park, or walking down the street, and seen a dog, and though (not in a sexual way, but in an appreciative way). "Man, that's a good looking dog!" By that you meant healthy, good clean coat, white teeth, etc, etc. And dogs are not the same species as humans.
Also, I think I recall there being being studies where, certain physical traits were universally found to be attractive. For women, it was large eyes, with slightly dialated pupils. An some other stuff. The pupil thing really stuck with me though. Not sure why we like dialated pupils though.