This is the original meaning of the word.
Later rights were added by latecomers for their own benefit, so it is difficult to understand the meaning of this word now. For example, the current village party secretary has more power than the village head, while the former village party secretary can only lead party member in the village, and the village head should have the greatest power (including the village party secretary, party member and villagers).
Why?
Because the party didn't mean to lead at first, she was just an organization, and the party member below was in a discrete state, and someone needed to sort out the records ... and eventually become the party's leadership.
For example:
There are many good articles in my computer. Now I'll sort them out and bind them into a book. At the moment, I became an editor, but I led the essay, not party member.