It's now a marathon, with Pa. the big prize

— -- Pennsylvania is the new New Hampshire.

Forget the frenzied cross-country campaign blitzes before Super Tuesday, or even the Ohio-Texas shuttle of the past month. For the next seven weeks, with brief breaks to visit Wyoming and Mississippi, Democratic presidential candidates Barack Obama and Hillary Rodham Clinton will be focusing on one state: Pennsylvania. They will be trekking from Pittsburgh to Philadelphia and back again in pursuit of the last big stash of delegates — 158 — that could give one of them a stronger claim to the presidential nomination.

Between now and the April 22 primary, there will be plenty of time for town hall meetings, diner drive-bys, local TV interviews, door-to-door canvassing and other staples of retail politics that late-voting primary states rarely see. The last time Pennsylvania had a competitive primary was 1976, when then-Georgia governor Jimmy Carter defeated Washington Sen. Henry "Scoop" Jackson and knocked him out of the race.

"People are telling me, 'My cousin's wife's niece wants to meet Sen. Obama,' " says state Democratic Party chairman T.J. Rooney, a Clinton supporter. "Show up at a diner and he just might walk in the door."

Clinton is leading the wave: On Wednesday, she sent daughter Chelsea to campaign at the University of Pennsylvania in Philadelphia. Soon, the candidates, their staffs, hordes of media and the attention of the political world will envelop the state of 12.4 million people.

"Are people coming? I should have tidied up. I should have Febrezed," jokes Mark Nevins, Clinton's Pennsylvania communications director.

Like in Ohio, demographics, economic issues and political leadership in Pennsylvania favor Clinton.

It is heavy on older and blue-collar voters and union households. Its popular governor, Ed Rendell, and recently elected Philadelphia Mayor Michael Nutter have endorsed Clinton.

Her wins in Ohio and Texas have bought her time to make her case to voters that she is the more experienced and tested candidate. Her campaign is hoping that it also gives Obama more opportunities to stumble such as the recent kerfuffle over his position on U.S. trade with Canada and whether his criticism of the North American Free Trade Agreement amounted to political theater or policy proposals.

"This is her state, her state to lose," says Terry Madonna, public affairs professor and poll director at Franklin & Marshall College in Lancaster, Pa. "There are a lot more elements in the environment here that favor her than him."

A recent Franklin & Marshall poll showed Clinton leading Obama 44% to 32%, with 20% undecided. The margin of error was +/-5.6%.

Obama's past victories suggest he will have support from African-American voters in Philadelphia and could benefit from strong anti-war sentiment in the city's suburbs.

Clinton "starts off every state with the backing of the political establishment," says Sean Smith, Obama's Pennsylvania spokesman. "We've overcome that in most of the states. This is not the year that you want to be the candidate of the establishment. Voters are hungry for change."

Obama still holds delegate edge

Winning Ohio and Texas was good news for Clinton, but it didn't help her catch up to Obama in delegates. On Tuesday, Clinton won at least 185 delegates and Obama won at least 173. He still leads her by 1,567 delegates to 1,462, including the party and elected officials known as "super delegates." It takes 2,025 delegates to win the Democratic nomination.

A victory in Pennsylvania wouldn't allow Clinton to catch Obama in the number of pledged delegates, nor would it give Obama the delegates needed to win the nomination. Most pledged delegates are awarded proportionally based on the margin of victory in congressional districts, which vary in the total number of delegates allocated to them. Because of that, Obama or Clinton could win the popular vote yet not reach the delegates they need. But winning such a big state — one considered a key battleground in the fall — would strengthen the argument each is making to super delegates.

"You've got to get momentum for whatever is going to come afterward," Madonna says.

Clinton needs a Pennsylvania victory to make her case to the party that she could win big swing states in the general election. Obama, who is favored to win the Wyoming caucuses Saturday and the Mississippi primary Tuesday, will argue that he has won more nominating contests (27 out of 42 so far), more total votes (about 13 million to Clinton's 12.4 million, not including Florida and Michigan where primaries did not award delegates), and more pledged delegates.

"The super delegates will consolidate around that person who has the most delegates. We think that will be us," Obama said Wednesday as he flew to Chicago.

Both campaigns are organizing their ground game in Pennsylvania: The Obama campaign says it trained 1,900 volunteers last weekend and the Clinton campaign says it has signed up 1,500. Clinton will open eight offices in the state by week's end; Obama has five.

The issues in Pennsylvania aren't likely to be much different than those in next-door Ohio: the economy, the Iraq war and health care. Pennsylvania's unemployment rate is relatively low, but like Ohio it has lost manufacturing jobs.

"The issues that are in the forefront are in the forefront for a reason," says Bar Johnston, an Obama volunteer organizer from Center Valley, in eastern Pennsylvania. "It's really bread and butter issues."

Rep. Chaka Fattah, a congressman from Philadelphia and Obama super delegate, says opposition to the war in Iraq will be a key distinction for voters choosing between Obama, who opposed the war as an Illinois state senator, and Clinton, who voted to authorize the war as a senator from New York. He says opposition to the war is "one constant in Pennsylvania."

Madonna says the economy, as it has elsewhere in the country, has eclipsed Iraq in voters' minds.

"It'll be about the economy, health care and environmentally friendly energy. You cannot talk about the environment in Pennsylvania without talking about job creation," he says. "If you link it to that, it's pretty popular."

How did we get here?

Pennsylvania initially didn't figure to play much of a role in determining the Democratic nominee.

The primary calendar, which was moved up and squeezed together more than ever before, was designed to pick a nominee in a hurry. But two history-making candidates, both with lots of money and appealing to different demographics, sent that plan awry.

Obama's ability to galvanize crowds, attract new voters and get them to turn out, helped him win caucus states 11-2. Clinton's sway with state political establishments helped her win big states such as New Jersey, Ohio and California.

Like a tennis game that keeps going back to deuce, the advantage in the Democratic nomination battle has gone back and forth. Obama still holds the advantage, but Clinton supporters such as Nutter are trying to cast the race as one in which both candidates now are starting virtually from scratch.

Momentum from Obama's 11-contest winning streak heading into Tuesday, or Clinton's big-state victories, won't last until April 22, he says.

"Whatever has happened in all these other places … is virtually immaterial and forgotten. It's not like the phone company where you get all these rollover minutes," Nutter says. "This is a whole new campaign." And a long one.

"Considering that Iowa voted eight weeks ago and it seems like two lifetimes ago to most people, yes, it's a long time," says Obama's Pennsylvania spokesman Sean Smith.

Are we there yet?

Jennifer Palmieri, a former strategist for the John Edwards campaign, says it's good for the Democrats that the battle will go on for at least another seven weeks.

"What you hope comes out in the primary is that your nominee is tested, they're fully vetted and they're battle ready," Palmieri says. "The debate has definitely intensified in the last couple weeks in a way we haven't seen before, and that's what it's going to be like in the general election. You would rather be dealing with issues in March than have John McCain raise them for the first time in September or October."

Clinton frequently points out that her husband, Bill Clinton, didn't wrap up the 1992 nomination until June. She neglects to mention, however, that he didn't even announce he was running for president until about 15 months before the election. She announced in January 2007, about 22 months before this November's election. By the time the earliest-ever, front-loaded compressed primary schedule kicked off in Iowa on Jan. 3, she had been campaigning for nearly a year.

State Democratic chairman Rooney worries that another seven weeks of intra-party battle will leave the candidates bloodied and the party broke.

"Part of me," he says, is looking forward to the Pennsylvania campaign "just for the sheer circus value of it all." But without a nominee, the state party can't begin focusing on the general election.

"The giant sucking sound will be money coming out of Pennsylvania" for the never-ending nomination battle — money that otherwise would go toward the general election campaign. The campaign for Pennsylvania is "arguably four weeks too long," Rooney says. "If it were more truncated, it would probably (be) to our benefit going forward, but try telling Barack Obama or Hillary Clinton that."

It's also a chance for the Democrats to organize and excite voters before the general election, when Pennsylvania will be a big electoral prize. That should be good for the party "under the right circumstances," Rooney says. "As long as there's nothing that can't be patched up."