Harrisburg, Pennsylvania  - "Madame president," a crowd of Senator Hillary Clinton supporters gathered ahead of Tuesday's Pennsylvania primary cheered as they welcomed the candidate for the Democratic presidential nomination to a rally in the eastern state's capital.

Supporters waved signs reading "Hillary, we've got your back." And the voters may indeed shield Clinton here, in a large state that is seen as key to her efforts to salvage her fight against Senator Barack Obama to represent their party in the November general election.

Recent opinion surveys show Clinton leading Obama in Pennsylvania by around 5 percentage points, but her advantage has narrowed considerably from a nearly 20 point lead several weeks ago.

Analysts say she must win big here to gain momentum in the nine remaining contests in the state-by-state nominating process that has become a drag-out fight, in which Obama holds a small lead in the number of delegates needed to clinch the nomination, but in which neither candidate has been able to decisively become the sole leader.

She must also convince the party leaders - known as superdelegates - who could decide the nomination that she can put a key swing state, such as Pennsylvania, in play in the general election and appeal to the party's base of working-class voters.

Some have called on the former first lady to step aside in the name of party unity. But her die-hard fans at an election eve rally would hear of no such thing, insisting that she continue on and arguing it helps strengthen the democratic process and prepare the ultimate candidate to do battle with the presumptive Republican nominee, John McCain.

They echoed Clinton's mantra that she is the most experienced candidate to take over the White House and move past the negatives of George W Bush's presidency.

"As the war drags on and the economy is going down the tubes, say what you will about her, but she knows the issues," said Sharon Stabinski, 46, a Harrisburg-based writer, who thinks Clinton needs a double-digit lead in Tuesday's outcome to remain a viable candidate.

Some staunch Clinton supporters such as Dana Thompson, 39, of York, Pennsylvania, think the senator from neighbouring New York should stay in the race no matter what.

"It makes me crazy when people say she needs to drop out. She's not that far behind - they're neck and neck," she said before a Clinton rally. "Why should she step aside? Women have historically stepped aside."

A few Republicans hoping to lend their support for the rival Democrats in November agree.

"I don't think she should stop. If it's close she has to keep going," said Melba Smith, 56, a Republican who cannot vote in the exclusive intra-party vote but hopes to cast a ballot for Clinton in November general election. "I wouldn't quit if I were her."

Clinton is widely expected to win in the populous north-eastern state, but it remains unclear whether the margin will be significant enough to help her candidacy. So the candidate did all she could on Monday as she crisscrossed the state to reach rare undecided voters and rally supporters to polling places.

"I hope you will ask (undecided voters) to think about it as a hiring decision because that's really what it is," Clinton told her supporters in Harrisburg. "There are two applicants left for the Democratic nomination. I want you to look at their resumes, I want you to look at their records, I want you to ask what they've done."

"Who's ready?" she asked before a list of key issues, such as turning around the economy and ending the war in Iraq, as her supporters' cheers became more and more enthusiastic.

"You're hired," at least one fan yelled from the audience. (dpa)