U.S. media balloting projections awarded Pennsylvania to Democratic presidential candidate Barack Obama on Tuesday night, a development which has narrowed the chance of Republican hopeful John McCain for an upset in the historic 2008 elections.

Pennsylvania is a key battle ground state, nicknamed the "big three" together with Florida and Ohio. Although the state went to the Democratic Party in the 2004 race, McCain had been campaigning hard in the eastern U.S. state in the last few weeks running up to the Election Day.

Analysts said that with Pennsylvania going to Obama, McCain still has a chance but can not afford the loss of any key battleground states which the sitting President George W. Bush won in 2004.

According to projections, Obama grabbed a total of 103 electoral votes. He is projected to win in Vermont (3), Connecticut (7), Delaware (3), District of Columbia (3), Illinois (21), Maine (4), Maryland (10), Massachusetts (12), New Jersey (15), Pennsylvania (21) and New Hampshire (4). McCain carried Kentucky (8), South Carolina (8), West Virginia (5), Oklahoma (7), Tennessee (11), Arkansas (6), Alabama (9) and Georgia (15) with a total of 69 electoral votes.

The victor needs 270 electoral votes to win the Electoral College and capture the presidency.

Under U.S. elections system, the president is determined not by the most votes nationally but by a majority of the Electoral College, which has 538 members. The number of electors is equal to a state's number of representatives (based on population) and senators (two per state) in the U.S. Congress. In addition, the District of Columbia has three Electoral College Votes.

Each state, except Maine and Nebraska, awards its votes to the candidate who gets the most votes in the state. Maine and Nebraska split them by congressional district.

The Election Day dawned as McCain, 72, faces an enormous task in trying to prevent 47-year-old first term senator Obama from winning the White House.

According to a pre-election tracking poll conducted by The Washington Post and ABC News, Obama leads McCain by nine percentage points and is ahead in enough states to push him well past the 270 electoral votes need to win.

McCain continues to campaign furiously in a swath of East Coast and Midwestern states in his final push in the hope of staving off defeat, but to keep the White House in Republican hands, he needs to hold virtually every competitive state as well as some in which Obama is leading.

Whoever wins the presidency will make history. Obama could become the first African American president in the nation's history. McCain, if elected, will be oldest president swearing in a first-term, while his running mate, Sarah Palin, will become the first woman vice president in U.S. history.

(Xinhua News Agency November 5, 2008)