The latest presidential debate between Democratic Party presidential contenders Barack Obama and Hillary Clinton appears to have done little to clarify a lengthy and bitter nomination fight that some Democrats fear may be helping the presumed Republican nominee, Senator John McCain.  VOA National Correspondent Jim Malone has more from Washington.

Candidates Obama and Clinton generally agree on issues like Iraq, health care and improving the U.S. image abroad.

But they sharply disagree on which of them would be the stronger Democratic candidate against Republican John McCain in the November election.

In the latest debate on ABC television, Clinton conceded for the first time that Obama could beat McCain if he becomes the Democratic nominee.

MODERATOR:  "Can he win?"

CLINTON:  "Yes, yes, yes.  Now, I think that I can do a better job, obviously, that is why I am here."

Obama found himself on the defensive for much of the debate over comments he made about bitter voters in small towns and inflammatory statements made by his former pastor, Reverend Jeremiah Wright.

But Obama said he would be able to overcome what he called the political distractions and would beat McCain in November if he becomes the Democratic nominee.

"When they see my track record and the work that I have done on behalf of people who really need help, I have absolute confidence that they can rally behind my campaign," he said.

The longer the race drags on, the more Democrats worry that both Obama and Clinton will be politically damaged if they win the nomination and vulnerable to Republican attacks.

"There is great concern among Democratic insiders that the Democratic contest has really resuscitated Republican prospects for November, that the contest has gone on too long, it has been too personal, it has created a deep division within the party and within party constituencies, and that it has become a real problem," said analyst Stuart Rothenberg, who publishes an independent political newsletter in Washington.

Rothenberg also notes that even though Obama has had a difficult few weeks, Clinton has been unable to capitalize in the polls.

"I do not think Senator Clinton has been able to take that much advantage of it, frankly," he added.  "It is more of a general election problem defining Barack Obama as a liberal.  That is a plus in the Democratic race.  The problem is, though, it is not a plus in the general election."

Clinton is favored in Tuesday's Pennsylvania primary, largely because of her advantage with white, working-class voters who have proven resistant to Obama's arguments that he best represents political change.

Quinnipiac University Pollster Peter Brown says Obama's lack of appeal to working class voters could hurt him if he becomes the Democratic nominee.

"The challenge for the Democratic Party once they end their nomination fight, whenever that turns out to be, will be bringing everybody home against McCain in November.  And what this indicates is that Senator Obama might have some problems in bringing home traditional Democratic voters," he explained.

Recent polls suggest that Republican John McCain has cut into the leads of both Obama and Clinton in head to head general election match-ups.

Stuart Rothenberg says at the moment McCain is the real beneficiary of the Obama-Clinton battle for the Democratic nomination.

"McCain is able to position himself as someone who is kind of above politics while they are involved in this back and forth, and he is talking about the economy and he is talking about the war and leadership and the like," he noted.  "And he just looks more presidential, so he is benefiting at the moment."

Obama continues to hold a lead in the overall delegate count, and Clinton needs a victory in Pennsylvania to keep alive her hopes of winning the nomination.

After Pennsylvania, the Democrats will compete in primaries in North Carolina and Indiana on May 6.  The primary season ends in early June and the Democrats hold their national nominating convention in late August.