Board of Elections investigator the Rev Odel Sterling III helps voters cast their ballots during early voting at the Cook County Administration Building, Monday, in Chicago. This year marks the first presidential general election to have early voting in Illinois. - AP

DECATUR, Georgia (AP):

More than 540,000 ballots have already been cast in Georgia, including many from the Democratic strongholds of metropolitan Atlanta in what could be an encouraging sign for Barack Obama's presidential bid.

Black voters have made up a disproportionately high percentage of early voters, accounting for 37 per cent of Georgia's early voters. Blacks represent 29 per cent of the state's 5.6 million registered voters.

With three weeks to go until the November 4 election, the number of ballots cast early in Georgia has already eclipsed the total number of early voters in advance of the 2004 presidential election.

Georgia elections officials say the number of early voters could ultimately top one million.

"Everything we can do to encourage early voters will alleviate the pressures on election day," said Matt Carrothers, a spokesman for Georgia's top elections official.

Obama's campaign said the high turnout is a signal of excitement surrounding the election. But Obama spokeswoman Caroline Adelman cautioned not to read too much into the voting bloc's racial break-up.

Historic turnout

"A lot of people are voting for Barack Obama and it doesn't matter what their background, their ethnicity is," she said. "It's going to be a historic turnout and we're thrilled to see people voting."

Republican Senator John McCain's camp said it was encouraged by the record early voting numbers. "This year is going to generate a historic volume of voters," said McCain spokesman Mario Diaz.

A new CNN/Time magazine/Opinion Research Corp poll of likely Georgia voters showed McCain at 53 per cent and Obama at 45 per cent.

The high interest among black voters could yield a higher overall turnout, which tends to favour Democrats. But Alan Abramowitz, an Emory University political science professor, said it's still too early to tell.

"It's a reflection of the enthusiasm gap that we've seen in a lot of polls," said Abramowitz. "Obama voters are more enthusiastic than a lot of McCain supporters. The more important question is whether it will translate into higher turnout."

So far, nearly 200,000 of the 540,757 of the early voters are black. Black females have outnumbered black males by roughly 50,000 votes. Many of the early voters come from left-leaning strongholds throughout the state.