Representative Democracy

• Democracy is of Greek origin.Jupiterimages/Photos.com/Getty Images
  
  The word "democracy" is Greek for a government of the people. A direct democracy occurs when every citizen directly votes on every issue. This is not practical for large populations. In a representative democracy, citizens vote for representatives who then vote on the issues for them. In the U.S., the Congress and the Electoral College are examples of representative democracy in action.
  
  

Separation of Powers

• The judicial branch interprets laws.Comstock Images/Comstock/Getty Images
  
  The U.S. government has three branches: executive, legislative and judicial. This creates a system of checks and balances that prevents any one branch from accumulating too much power. Each branch has its specific function. The legislative branch makes laws. The executive branch enforces laws and the judicial branch interprets laws.
  
  

Federalist Model

• Federalism allows lawmakers to meet the needs of specific regions.Thomas Northcut/Photodisc/Getty Images
  
  The United States is divided into 50 separate states, and each state has its own distinct government. In a federalist system, power is divided between the state governments and federal government. For example, the federal government coins money and regulates international trade while state governments manage public education. Some powers are shared like taxation.
  
  

The U.S. Constitution

• The preamble to the Constitution outlines its purpose.Jupiterimages/liquidlibrary/Getty Images
  
  The U.S. Constitution outlines the powers of each branch of government. The Constitution also includes the Bill of Rights to guarantee civil liberties for all U.S. citizens. It is the job of the U.S. Supreme Court to interpret the Constitution and it is the president's job to ensure those interpretations are upheld.