Washington -- On Election Day, when American voters mark their ballots for their favorite presidential candidate, they are, in actuality, voting for a group of state electors. These electors are pledged to vote for that candidate in the Electoral College, the body of representatives that really elects the president and vice president.
Set up in the early days of the republic, the Electoral College currently has 538 members. Each state is represented by electors in equal number to the number of senators and representatives that represent that state in Congress. The District of Columbia -- where Washington is located -- has no voting representation in Congress, but nevertheless has three electoral votes. The candidate who wins the presidency is the one who receives an absolute majority (at least 270) of the electoral votes.
Under this electoral system, it is possible to win the presidency without winning the popular vote. This happened most recently in 2000, but it has also happened three other times in the history of the United States. This anomaly occurs because nearly all the states use a "winner-take-all" system so that whichever candidate wins the popular vote in that state gets all its electors in the Electoral College. The only exceptions are the states of Maine and Nebraska, where two electors are chosen by statewide popular vote and the remainder by the popular vote within each congressional district.
Consequently, political parties must consider each state to be a separate race, keeping in mind that it is not the national total of votes that counts; it is how many electoral votes a candidate receives that will determine who goes to the White House. Candidates must run both a national campaign in which their messages are carried by the country's mass media and more targeted state races that address local and regional issues and concerns.
Many states, by virtue of their demographics or economic profile, will predictably favor a certain candidate or party. In recent years, there has been a wide discussion of so-called red and blue states, states that have tended to vote in majority for Republicans (red) or Democrats (blue). The maps illustrating these distinctions show most blue states along the coasts and most red states in the south and center of the country. Those states that are too hard to predict -- known as battleground or swing states -- tend to be the focus of many of the resources of both campaigns.
Battleground states, where the candidates are currently running within a few percentage points of each other, can change from election to election or even during a single election season. In 2004 there were 10 battleground states: Florida, Ohio, Pennsylvania, Iowa, Minnesota, New Hampshire, New Mexico, Oregon, West Virginia and Wisconsin. Together, these 10 states represented 116 of the 270 electoral votes needed to win.
Campaign strategists must calculate how much time and money a candidate needs to spend in any given state in order to have the best chance of winning. In 2004, President George Bush and Senator John Kerry made numerous visits to battleground states like Pennsylvania and Ohio during the campaign. In addition to the presidential candidates themselves, their vice presidential running mates, family members and other surrogates such as popular local politicians made speeches on behalf of the campaigns in the various states.
In a close race, voter turnout is decisive, so both campaigns organize get-out-the-vote efforts to identify supporters and either get them to the polls on Election Day or encourage them to vote early by mailing in absentee ballots. Both parties also have active voter registration programs aimed especially at communities likely to favor their candidates.