Washington, Feb 4: 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 Supporters of the now-withdrawn John Edwards appear to have been shared evenly by the two leaders who have accused each other of leading a divisive campaign.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.