Electoral College of the United States
In the U.S. Constitution the election of the president of the United States is actually done indirectly. This task is performed by a body of people called the Electoral College. The membership of the Electoral College is voted on every four years (leap years - or years that are evenly divisible by four) by the people in the individual states. The number of electors from any particular state are based on the number of representatives plus senators sent to Congress from the state in question. This means that there will be a minimum of three electors from any given state (one representative and two senators).
Thus, in a presidential election, people are not voting for a person but a slate of electors who are committed to voting for a particular presidential and vice-presidential candidate at a meeting of the Electoral College. (Nevertheless, there are, at the time of this writing, two states - Nebraska and Maine - that split their electors based on the percentage of popular votes that the candidate receives.) The person receiving a majority of votes in the college becomes president. Should there be no candidates to receive a majority, the election is thrown into the House of Representatives. There have only been two elections sent to the House, the election of Thomas Jefferson in 1800 and the election of John Quincy Adams in 1824.
There has been one amendment to the Constitution to affect a change in the way the system works. In the original system the electors simply had two votes. Whoever got the majority was made president, whoever got the second most votes automatically became vice-president. Although this may sound like a fair way to handle election to the high office, it was found that the president was often saddled with a vice-president who was completely against his policies. This might also cause the party behind the vice-president in such cases to actively work for the demise of the president. To avoid this unseemly situation Amendment XII was approved by congress and ratified by two-thirds of the states.
The twelfth amendment to the Constitution states that the electors "shall name in their ballots the person voted for as President, and in distinct ballots the person voted for as Vice-President." Doing this ensures that the president and vice-president will be a team rather than adversaries as the electors are chosen based on the candidates that they support.
The question is often asked as to why the United States does not simply go to a popular vote for the president. Throughout history the candidate receiving the most popular votes has nearly always also received the most electoral votes. Yet the system was originally put into place to ensure that the wishes of states and regions would also be taken into account. A state that has only one representative and two senators might seem to have a very small weight in the scale of electors, especially when compared with a populous state like California. (Representation in the House is, in fact, based on population.) However, the weight of the small state is actually three times greater than it would be in a vote based purely on population because its two senators count toward its number of electors. Since many of these small states can vote together, they can protect their interests against a single large state which might attempt to impose its views or demands on the nation at large.