Interestingly enough,
advid is correct for even more reasons than he states.
A man named Michels created something known as the Iron Law of Oligarchy while observing the SPD(Social Democrats, Sozialdemokratische Partei Deutschlands) of Germany. Michels observed that there is an inherent flaw in the idea of mass-democracy that leads to the constant contradiction or paradox if you will:
Why does the equality party, the party of the people, act bureaucratically in its internal behaviors?
In other words, in a democracy every member of the governed should have equal say in the policy of the state. While the United States creates a very close (and as some would argue, the closest possible) proximity to a democracy, it still creates political ruling classes.
This contradiction was at the heart of early Green Party policy in Germany, but as the Greens soon found out: nothing gets done in a true democracy.
The same rule holds true in any human society. The organization efforts needed to get 250 million people to all behave in a certain manner would take years, just look at our Census. advid is very correct in saying that the United States is no democracy, and all American citizens should be very grateful for that fact.