With less than six weeks until the Nov. 4 election and the key battleground of Pennsylvania looking very much up for grabs, the party pros are jittery.

On the Democratic side, state party chairman T.J. Rooney says that while he's much impressed with Sen. Barack Obama's big field organization, he frets that Obama is running too independently of the established party apparatus.

"There is very little collaboration and coordination this year," Rooney said.

On the Republican side, former Gov. Tom Ridge says that while he's buoyed by polls showing Sen. John McCain closing the gap with Obama, he worries about McCain's "late start" in organizing his field operation and about the big gains Democrats have made in registering voters.

"We know we've got a steep climb," Ridge said. "We still think it's winnable."

Much is at stake. Pennsylvania is among the handful of states that could swing either way and decide the presidency.

The pros recognize that what Obama and McCain do on the national level - in TV ads, in fund-raising, in debates - will largely determine the outcome, here and nationally.

But efforts the candidates make on the ground in Pennsylvania to identify their likely voters and get them to the polls may be worth a percentage point, or two or three - enough to tilt a close race. And that's one area over which the in-state pros can have influence.

McCain and Obama have organized their state campaigns in different ways.

McCain's is the more traditional, relying heavily on the state's Republican structure to fill the ranks of campaign volunteers.

Jon Seaton, McCain's regional campaign manager for Ohio and Pennsylvania, said the McCain effort was "very similar" to the Pennsylvania campaign run by President Bush in 2004.

One difference is size. Bob Asher, a longtime GOP fund-raiser and cochairman of McCain's state effort, said: "Bush had a far larger staff. This is a leaner campaign. . . . We will never get more than 50 percent of what Bush had as far as personnel."

The national campaign staff is clearly in charge, but it has let in-staters make many of the local decisions, Ridge said.

"I think, to this point, they have been pretty good about letting Pennsylvanians run a Pennsylvania campaign," the former governor said. "As long as they don't micromanage, I think we'll be OK."

Still, he said, "I think in terms of ground troops and organization, we're still playing a little bit of catch-up."

Obama's campaign, more than McCain's, has run on its own track. Rooney called Obama's operation "more independent" and "more autonomous" than any campaign he had ever seen.

"It is very much different from campaigns in years past," Rooney said. "That is not to say it is good or bad. That is just a statement of fact."

Rooney said his own direct involvement with the Obama staff was "limited."

That limited involvement has unnerved some party insiders. David L. Cohen, Gov. Rendell's closest counselor over two decades in politics, said he hears all the time from Democratic insiders - some miffed because Obama doesn't appear to want their help or advice - that the Illinois senator is somehow "blowing it" in Pennsylvania.

Cohen said he tells the worriers, "Calm down, calm down, take a breath." He says he can't remember a better-run campaign than Obama's.

All this, Cohen suggests, is the "normal carping" in a tight campaign - the "tension" that always exists between a party's national candidate and its in-state leaders.

Party leaders on both sides are concerned about additional races that could be affected by results at the top of the ticket, including contests for three states offices, a battle for control of the state House, and several close congressional elections.

Rooney said Obama's decision not to pool funding efforts and strategic ideas had left some in the party feeling "on our own." But he said he was optimistic that what appeared to be an "incredibly good" Obama field operation would "lift all boats" and aid the party's candidates.

Sean Smith, Obama's Pennsylvania spokesman, said Obama chose not to run a coordinated campaign because of his vow not to take donations from political-action committees, or PACs. The state Democratic party is accepting such donations from unions, liberal groups and other organizations.

Both McCain and Obama have assembled campaign staffs led by an out-of-stater.

Seaton, who is based in Columbus, Ohio, ran McCain's effort in the Iowa Republican caucus in January. He has had limited experience in Pennsylvania politics.

His No. 2 man, based in state, is Ted Christian, who was a field staffer for former New Jersey Gov. Christine Todd Whitman when she was reelected in 1997. He was executive director of that state's Republican Party in 1999.

Christian said the Pennsylvania team includes people with a mix of GOP pedigrees. Some are long-time Ridge loyalists. Some were backers of former New York City Mayor Rudolph Giuliani - the early favorite of many in the state's GOP establishment - who dropped out of the race in January and threw his support to McCain. Some were allies of former U.S. Sen. Rick Santorum, who lost his seat in 2006.

The Obama staff is led by Craig Schirmer, who ran Obama's primary efforts in Wisconsin, South Carolina and North Carolina.

Obama, in the April Democratic primary, found himself up against most of his party's power brokers, including Gov. Rendell, and some primary wounds appeared slow to heal. But the Obama staff now includes several members of Rendell's former gubernatorial campaign team, including Kevin Kinross, who is heading up Obama's work in Western Pennsylvania.

Smith said Obama has opened an unprecedented 72 offices across the state and has organized 569 neighborhood-based teams of volunteers.

"We are creating the largest field campaign that anyone has ever seen in Pennsylvania," he said.

The biggest thing that Obama may have done to boost his chances - and that of other Democrats on the ballot - is to enroll thousands of new Democrats through his campaign's voter-registration push over the last year.

Democrats now have 4.3 million registrants - 1.1 million more than the Republicans. That's double the edge that Democrats held in 2004, when Sen. John Kerry beat President Bush in the state by 144,000 votes.

Republican and Democratic leaders said that with 47 days remaining before the election, there is still much work - and worrying - to go.

U.S. Sen. Robert P. Casey Jr., Obama's top in-state supporter during the primary, said he was concerned about Obama's progress among socially conservative Democrats in his home area of Scranton and in much of Western Pennsylvania.

"There is still a good deal of work to be done," he said. "I think [Obama] is going to win the state, but we have some work to do."

Asher, while optimistic that McCain could make inroads among Democrats and independents in the key Philadelphia suburbs, said he was concerned about making up for the slow start McCain got in organizing his campaign.

"I do think we are getting it together," he said cautiously. "I will say this: We are in a heck of a lot better shape today than we were three months ago."