In a democracy a constitution draws its power from what

The correct answer is the people, that in a democracy the constitution derives its power from the people.

The constitution of the United States announced that the power to the government comes from the people of the United States. Democracy in the United States is present in the form of representational democracy (where citizens elect their delegates to run the administration) and not in the form of direct democracy (where rules and other decisions are performed predominantly by the majority of votes.