As the US elections on November 4 loom, US media and political analysts have begun to speculate on the results by coloring 50 states and the District of Columbia in red, blue and purple in anticipation of the outcome.

Red states refer to those whose voters predominantly favor the Republican presidential candidate, while states whose residents overwhelmingly support the Democratic presidential candidate are usually in blue. Accordingly, light red and light blue represent Republican-leaning and Democratic-leaning states, respectively.

The term of purple states, or swing states, is used to designate states whose voters do not show a clear preference toward any candidate.

The US news media has used colored maps to depict voter preferences graphically in the presidential elections for a long time. But the terms of red, blue and purple states were coined during the 2000 election by a TV anchor.

In general, red states and blue states have several demographic differences from each other. Seen from the perspective of the 2004 presidential election, states with more voters with higher education, minority background or lower and middle income favored Democratic candidate John Kerry, while those with the opposite voter composition supported Republican George W. Bush.

Given the general nature and common perception of the two major parties, red states also imply a conservative region or a more conservative type of American, while blue states refer to a more liberal region or a more liberal type of American.

Such identification is subject to change as a state's demography, dominant conception and voting record change.

Traditionally, the practice of designating a state as "red" or "blue" is based on the "winner-takes-all" method that is used by most states and the District of Columbia to award electoral votes to presidential candidates. For example, if a Republican nominee wins a majority of popular votes in a state, he takes all of its electoral votes and turns it into a red state.

According to the results of previous presidential elections, southern states, including South Carolina and Texas, with strong conservative bases have shown consistent support for Republican candidates and therefore are termed red states. Northwestern states, typical blue states, have awarded their electoral votes to Democratic nominees in recent decades.

It can be also found that basically, the Democratic Party is more appealing in coastal and industrial states and the Republican Party has more solid bases in inland and agricultural states.

However, during the presidential campaign, especially as election day looms, presidential candidates focus most resources on campaigning in large swing states that might play key roles in determining the outcome.

According to past voting records, states like Missouri, Florida, Ohio and Pennsylvania did not show loyalty to any party but usually their election results were considered decisive.

Recent polls have found that Democratic presidential candidate Barack Obama leads in all states that the party's former nominee Kerry won in 2004, and he has also gained the upper hand in six Republican-leaning states that Bush won, namely Iowa, North Carolina, Florida, Colorado, New Mexico and Nevada.

Virginia, which has stood behind Republicans in the past 10 presidential elections, has become a battleground that Obama and McCain are competing for and may serve as a vane in the coming elections.

(Xinhua News Agency November 4, 2008)