FACTBOX: Electoral College elects U.S. president

(Reuters) - The Electoral College actually elects the next president of the United States, not the popular vote. Here are some facts about the Electoral College:

* There are 538 members of the Electoral College, allotted to each of the 50 states and the District of Columbia based on their representation in the U.S. Congress. The smallest states have three members while the largest state, California, has 55. Washington, D.C., which has no representation in Congress, has three, the same as the smallest state.

* It takes 270 electoral votes to win election. The electors are pledged to one candidate or the other but there is no federal law requiring them to vote that way. There have been several incidents in which a "faithless elector" has voted for someone other than the major candidates.

* In 48 states and the district, the candidate who wins the popular vote wins all of the state's electors. Nebraska and Maine have a proportional system of awarding electors.

* Electors, who are picked by the respective political parties, make two selections -- for president and for vice president. They may not vote for two candidates from their own state.

* Because a candidate could run up a big vote count in some states but lose others by narrow margins, the winner of the popular vote might not have the most electoral votes. The Electoral College has three times picked the candidate who lost the popular vote -- Republicans Rutherford Hayes in 1876, Benjamin Harrison in 1888 and George W. Bush in 2000.

* The Electoral College meets in each state to cast its votes on a Monday early in December after the November popular election. The votes are then tallied in a joint session of Congress on January 6 of the following year.

* If no candidate receives a majority of the electoral votes, the House of Representatives chooses among the top three candidates with each state having only one vote. If no vice presidential candidate receives a majority, the Senate decides between the top two candidates.

* The House has twice decided the outcome of the presidential race -- in the 1800 and 1824 elections. The Senate decided the vice presidency once, in the 1836 election.

* This unique system was the result of a compromise by the writers of the U.S. Constitution in the 18th century between those who wanted direct popular election and those who wanted state legislatures to decide. One fear was that at a time before political parties, the popular vote would be diluted by voting for an unwieldy amount of candidates.

(Writing by David Wiessler; Editing by Doina Chiacu)

(For more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)