SCOTT SIMON, host:
This is WEEKEND EDITION from NPR News. I'm Scott Simon. Coming up, Syria opens its borders to Arabic language students.
But first, another bout of sniping this week between Senators Barack Obama and Hillary Clinton in the run-up to the Pennsylvania primary on April 22.
The candidates for the Democratic presidential nomination are competing hard for the support of blue-collar voters and got into a spat about comments made by Senator Obama at a fundraiser in San Francisco.
The senator said Pennsylvanians are bitter after years of job losses, and they, quote, "cling to guns or religion or antipathy to people who aren't like them or anti-immigrant sentiment or anti-trade sentiment as a way to explain their frustrations."
Senator Clinton jumped on those comments yesterday. She said she didn't find voters bitter but optimistic and resilient.
Senator HILLARY CLINTON (Democrat, New York; Presidential Candidate): Pennsylvanians don't need a president who looks down on them. They need a president who stands up for them.
SIMON: And Senator Obama had more to say about this in Indiana, which holds its primary on May 6th.
Senator Barack Obama (Democrat, Illinois; Presidential Candidate): For 25, 30 years, Democrats and Republicans have come before them and said we're going to make your community better, and nothing ever happens. And of course they're bitter. You would be, too. In fact, many of you are.
SIMON: On Wednesday, Senator Clinton and Obama will debate in Philadelphia.
NPR national political correspondent Mara Liasson was in Pennsylvania this week and joins us now. Thanks for being with us, Mara.
MARA LIASSON: Nice to be here, Scott.
SIMON: And what does this (unintelligible) tell us?
LIASSON: Well, it tells you how intense the campaign is getting and how hard these two candidates are competing for the votes of blue-collar voters in Pennsylvania and other states.
It also tells you something else: McCain, believe it or not, John McCain, jumped into this spat and said that Obama's comments show how out of touch he is with regular folks. It also shows you that the line of attack that's being taken against Obama in the primary and will be taken if he's the nominee is that he's an elitist, he can't relate to ordinary working-class folks, and of course for any Democrat, that is the path to victory in the fall. They have to get votes from those kinds of people if they're going to win the big swing states.
SIMON: Remind us of the critical importance of Pennsylvania to both the Obama and Clinton candidacies.
LIASSON: Well the Pennsylvania primary is important to both of them. It's very big, it has a lot of delegates. It is actually a chance for Obama to, if he could win or do well - don't forget, the loser gets delegates in the Democratic system, too - that he can add to his delegate count but also that he could prove if he does well in Pennsylvania that he can relate to those white, working-class voters.
In the past, he's built his victories in primary after primary with the support of upscale, affluent, educated voters. Senator Clinton has won the votes of more blue-collar, lunch-bucket Democrats.
So he wants to prove that he can do well with those people. For Senator Clinton, doing well in Pennsylvania would add to her popular-vote total, close the gap with Barack Obama and make it easier for her to argue to the superdelegates that they should swing their support, even though he's ahead in the pledged-delegate count.
SIMON: And what's the movement been in superdelegates this week?
LIASSON: Well since February 5th, the movement has been very slow but very steady towards Barack Obama. Her lead in the superdelegates is now under 30, and there are about 300 of the 796 superdelegates that are still uncommitted, and 65 percent of those uncommitted superdelegates are from states that Obama won.
Now, it doesn't mean that all of them are going to go for him, but it shows you the uphill climb Senator Clinton has.
SIMON: And on the campaign calendar after Pennsylvania, there is…
LIASSON: There are 10 more contests, obviously Indiana, where Obama was speaking, West Virginia, Kentucky, North Carolina, Puerto Rico, Guam, but it's very likely that these two candidates will split them in half, and this race won't be any less clear or decisive when the primary season is over on June 3.
SIMON: NPR's Mara Liasson, thanks so much.
LIASSON: Thank you, Scott.