Pollsters predicted a tight race between democrats Hillary Clinton and Barack Obama and a formidable lead for old Republican warhorse John McCain as the presidential hopefuls made a frantic push to woo voters ahead of the crucial 'Super Tuesday' showdown in 24 state primaries.
Obama, bouyed by the South Carolina victory, is looking to close the gap with Clinton in the Tuesday poll in 22 states with more than 1,600 delegates at stake.
But with their competing themes of experience vs. Change dividing the Democrats, ABC News/Washington Post poll says the 60-year-old former first lady has 47 per cent support against Obama's 43 per cent. Supporters of the now-withdrawn John Edwards appear to have been shared evenly by the two leaders who have accused each other of leading a divisive campaign.
Sharpening her diatribes against Obama, 20 years her junior, Clinton compared him to the unpopular President George W. Bush for his lack of experience.
"We cannot afford to elect someone as we did with George Bush and then be somewhat surprised by the decisions that are made," she said today.
Obama admitted that Clinton was a "favourite" and he the "underdog" and unleashed star campaigners Senator Edward Kennedy, influential brother of former US President John F Kennedy, the slain leader's daughter Caroline and talk show host Oprah Winfrey to convince undecided voters.
The ABC poll predicted 2-1 advantage for 71-year-old John McCain in the Republican race with a boost from former New York Mayor Rudy Giuliani's departure, continuing a remarkable surge for the Vietnam veteran that began with his New Hampshire and South Carolina victories.
"I assume I will get the nomination of our party," the Arizona senator McCain, who now has 48 per cent of voters favouring him, double the support of his closest competitor, Mitt Romney, said. Mike Huckabee trailed at 16 per cent.
On Tuesday over 1,000 convention delegates will be at stake. A total of 1,191 delegates are needed to secure the nomination at the Republican national convention.
In the overall delegate race, McCain has 93, Romney 59 and Huckabee 40. Paul has four and Giuliani one.
Romney, 60, however got a minor boost today with a win in Maine primary. "This is a people's victory. It is also an indication that conservative change is something that the American people want to see," he said.
Maine's Republican primary, however, is non-binding, with the 21 chosen delegates free to vote for whomever they chose at the state convention.
The Democratic Party will hold its primary in Maine on February 10.
With the race issue evident in the Democratic race, the ABC poll said African American Obama leads by 2-1 among the community (including black women), by 10 points among men and by 12 points among independents. He's also ahead by 18 points among Democrats who describe themselves as "very" liberal.
But Clinton is maintaining her advantage in other groups She leads Obama by 15 points among women and 23 points among white women.
She also has more committed support-- 62 percent of Clinton voters say they strongly support her, compared with 49 percent of Obama's. Both well outstrip McCain's 38 percent strong support. The difference was within the poll's plus or minus four-point margin of error.
Amid fears of recession, the economy continues to advance as the single biggest concern in the election, to Democrats and Republicans alike.
The number of Americans who call it the top issue in their vote has risen steeply from 11 percent in September to 29 percent last month and a new high of 39 percent now.
A total of 2,025 delegates are needed to secure the Democratic presidential nomination.
Top Democrat and Republican White House hoepfuls were criss-crossing the country to reach out to people ahead of Tuesday when nearly half of the country will vote.
Once formally nominated, the Democratic and Republican candidates will face off in the November 4 general election.