Contrary to what many people believe the form of government in the united States is not a democracy. The foiunding fathers established a republican form of government.
In democracies it is the will of the majority that decides, while in republics it it the representatives of the people who make the important decisions.
In Article 4 Section 4 the Constitution mandates that the states have a republican form of government. Many states violate this provision by allowing the people to votes on referendums which is a democratic process which violates the principles of republicanism.