You're right. "Power" in the abstract is a modifier for human behavior--it doesn't exist until vested into a person. Any resulting corruption is a product of how it's used, which in turn is a function of its generally corrosive effect on the morals and scruples of the people who wield it.
POSITIONS of power on the other hand are things unto themselves, and you're absolutely right that those get systemically tainted with corruption independently of the people who hold them.
Now pardon me while I go weep for any good-natured soul who enters politics with the sincere intention of fighting its systemic, institutional corruption. They have only 2 paths: get chased out by corruption, or become corrupt themselves.
