dwipper said:
Assuming a bit of both, I usually inperpret it to be power derived from the people, not by coercion or manipulation, usually through democratic processes.
When the power in question is in a monarchy as opposed to a democracy, I suppose that legitimate power may come from the blood-line of the royal family.
What I'm trying to say is that legitimate power will come from what the governmental system (or other system, if the context does not refer to the government) is supposed to support.