What does Clinton's victory in Pennsylvania mean?

I was taking a few days off when the long-awaited Pennsylavania primary took place, now that I'm back in the thick of things and as I listen to the political pundits, I wonder about the interpretation of Clinton's victory on Tuesday. 

Let's first say a few words on the breadth of her lead over on Obama. A month before the primary, the Senator from N.Y. was way ahead of her opponent in the polls, probably by more than 20%. As the campaign progressed, Obama managed to narrow the gap but he has not managed to close it completely. There has been much talk about this: 

-  does this mean that he does not have what it takes to win overwhelmingly the support of the working-class whites (a critical majority of Democrats in Pennsylvania as well as in Ohio, which Obama also lost to Clinton in March in a very similar scenario)? 

-  did he suffer from his comments on the "bitterness and clinging attitude" of the Pennsylvanians? For the debate on class that has followed read the Lexington column in The Economist.

-  should we see it as a proof of Clinton's strength? 

Only one thing is certain : the show goes on. Next stop : Indiana.  

After spending three weeks lowering expectations (at first they were counting ona double digit lead and she then claimed that even a small lead would prove that her candidacy was extremely strong since she had been out-spent one to three by Obama), Clinton now claims that this is a decisive victory and she is trying to use it to push her agenda : seating the Florida and Michigan delegates at the convention. This would allow her to argue that her pledged delegate count is extremely close to Obama's. In so doing, she will try to present the final result as a virtual tie (= a quasi tie ) and thus make her I-have-experience-and-am-electable case to the superdelegates and allow them to support her en masse without seeming to disregard the so called popular vote. This is the only solution for her to win the nomination.  

This is an entertaining and somewhat relevant critcism of the campaign rhetoric of Clinton : 

In the first segment Hillary Clinton's speech is compared to the character Tom Joad in The Grapes of Wrath by John Steinbeck (an excellent novel in which the Depression is not only the backdrop but the central theme of the story. 

Did you notice how the Clintons and their supporters are wooing the superdelegates and insisting on their special position as arbitrators and moderators, more capable of making the right decision for the party.

Meanwhile on the Republican side, John MacCain is already campaining in the South and he has been touring African-American areas, he has been refining his economic policy package. The Democratic fight is providing him with a unique opportunity to get ahead in the national campaign.