NEW YORK: Barack Obama was closing fast on Hillary Clinton for the vital Pennsylvania primary on Tuesday, as he emerged from the ugliest week in their 15-month race literally brushing off her last-ditch attacks.

Only a victory in double figures will keep the former First Lady credible in the battle for the Democratic party nomination to fight for the White House and she is slipping rapidly in most polls. Six weeks of campaigning since the last primaries pitted the two in an increasingly vicious and personal brawl have failed to dent Obama’s rise.

But after a week that was more bruising for Obama, he emerged ahead of Clinton in a poll of Democratic voters about the nomination nationally, and ahead of both Clinton and Republican rival John McCain in national presidential polls and surveys of the candidates’ honesty and favourability, while gaining on her in Pennsylvania itself.

Clinton is still expected to win the state, but most polls there now have her at most 5 per cent ahead, with some predicting a photo-finish and one a long-shot Obama victory.

While Obama is drawing crowds to big events, his campaign team are scrabbling for undecided voters in white rural areas and small towns, until recent weeks solid Hillary country. Their goal is to shrink Clinton’s margin of victory to the point where it looks humiliating, even terminal. ‘If we’re going to keep this in single digits, we’ve got to mine every vote we can,’ said Sean Smith, a spokesman for the Obama campaign.

Obama’s crowd of 35,000 on Independence Mall in Philadelphia on Friday night is not quite up with the Pope’s expected congregation of 60,000 in New York’s Yankee Stadium on Sunday, but it gave him the look of being populist and presidential.

With Obama ahead in the count of supportive party delegates and the popular vote, Clinton’s campaign is taking on a desperate edge. Even in a week of taking bruising assaults on the trail and in their 21st televised debate, he still garnered the endorsement of six more super-delegates and rock idol Bruce Springsteen.

Clinton has the support of Philadelphia mayor Michael Nutter, but has been accused of ‘McCarthyism’ by at least one commentator by appearing to side with right-wing enemies against her rival senator.

‘Clinton has broken an unwritten rule of politics, which is that you do not disadvantage a member of your own party and side with your opponents,’ said Gary Hart, a former Democratic presidential candidate, who has endorsed Obama.

Despite answering ‘Yes, yes, yes’ when asked if Obama was fit for the presidency during their ABC network debate last week, Clinton has, among others, boosted McCain’s credibility by praising his experience and qualifications to become commander- in-chief.

‘Hillary Clinton has philosophical differences with McCain, far-right-wingers Pat Buchanan and Rush Limbaugh and the conservative talking heads on Fox TV,’ Washington Post columnist Colbert King wrote in an editorial on Saturday. ‘But they and Clinton have a common enemy: Obama. Their allegiance to the goal of bringing him down makes them compatriots.

‘Buchanan, who proclaims that “reverse discrimination is pandemic”, goes into overtime, branding Obama as a left-wing zealot while praising Clinton as a paragon of Middle American virtues,’ he added.

Clinton accused Obama of doing too much complaining after he spent most of the ABC debate on the ropes over his political and religious links and his comments that small-town Pennsylvanians are bitter and cling to guns and religion.

But he virtually rapped back from it on Friday in North Carolina with hip-hop moves taken from music mogul Jay-Z that had a crowd - liberally peppered with Hillary’s grassroots white women - on their feet and cheering wildly.

Drawing shrieks of laughter from a crowd in Raleigh, as he dived south briefly from Pennsylvania for an event ahead of the North Carolina primary on May 6, Obama joked about the debate. He bit his lip, then gave one of his wide, electric grins, before miming a hand stabbing with a dagger and said: ‘Hillary looked in her element. Y’know, that’s her right, to twist the knife a little bit.’

Then he deadpanned and mimed brushing dirt off each shoulder, a move one of his rap heroes, Jay-Z, uses to dismiss the negative sentiments of anyone ill-disposed towards him and what he stands for. The crowd went wild and commentators declared it a seminal moment in the campaign, mixing his charisma, popular culture, youth and resilience to a bruising campaign.

Clinton had earlier declared: ‘I’m with Harry Truman on this - if you can’t stand the heat, get out of the kitchen... just speaking for myself, I am very comfortable in the kitchen.’

Obama was effectively saying I am, too - name your kitchen. —Dawn/The Guardian News Service