What is the basis for our political power?
#We. The. People.
The basis of our political power is not what we do, but the mere fact that we exist. Our power arises not by what we do, but simply by our being. The religious among us would say it is "God given". This is the fundamental concept of "Democracy".
Contrast with "Monarchy", where political power is considered to flow from the King and the basis of that political power is "Divine Right".
The duty that the nobility owed to their king is the same duty that the government owes to the people. Democracy is the idea that We The People are the royals, and not the peasantry.