U.S. Sen. Hillary Clinton (D-N.Y.) won Pennsylvania by 9 percentage points over U.S. Sen. Barack Obama (D-Ill.) on April 22 in part because she leaned heavily on the state's Democratic leaders, nearly all of whom were supporters.

If Barack Obama, who last week secured enough delegate support for the Democratic presidential nomination, wants to have the same kind of success against U.S. Sen. John McCain (R-Ariz.) this fall, he might need to do the same.

The presumptive Democratic presidential nominee will try in the coming months to merge his largely grassroots operation in Pennsylvania with the party's existing Democratic machine, led by Gov. Ed Rendell.

The combination of the two forces, who together earned more than 2.3 million votes in the primary, might be necessary to defeat the Arizona senator, whose campaign has said it thinks it can win Pennsylvania by exploiting the Illinois senator's weakness with white rural class voters and former Clinton supporters.
 
Obama would gain a huge advantage if he can tap into Clinton's political machine, said Muhlenberg College pollster and pundit Chris Borick. Most of the state's high-profile politicians are Democrats, including Rendell and U.S. Rep. John Murtha (D-Johnstown), he said.

The additional surrogates, particularly Murtha, could help Obama in the working-class regions he "got killed in" this April, Borick said.

"A guy like that help helping you in the ground game is going to be essential," he said.

Party members don't doubt most of the state's high-profile Democrats, including state lawmakers and congressmen, will campaign vigorously on behalf of Obama.

But whether rank-and-file party members, who do the vast majority of campaign legwork, volunteer for Obama is a bigger question.

They must put aside hurt feelings left over from a hard-fought five-month primary and cooperate with Obama volunteers to successfully integrate the two campaigns.

Former Clinton Pennsylvania Director Mary Isenhour, who said she supports Obama "110 percent," thinks hurt feelings will fade as the general election, and the prospect of a McCain presidency, nears.

She compared what happened between Clinton and Obama to the heated 2002 gubernatorial battle between Rendell and and now U.S. Sen Bob Casey Jr. (D-Scranton).

"In the fall we came together," she said, "and elected the best governor I think we've ever had in this state."

The ability of the two sides to get along, however, might have more to do with the clash of styles between the party's old and new guards, according to Greg Stewart, co-chairman of Obama's Pennsylvania grassroots campaign.

He said older Democrats, who mostly supported Clinton, hold leadership in most of the state's local parties and have traditionally coordinated local campaigns for presidential candidates. But new party members, who mostly support Obama, might try to supplant them because their candidate won the nomination, he said.

Precinct leaders who have held their position for decades might suddenly find themselves challenged, Stewart said.

"There will be tension between the old ways of doing things and the grassroots way," he said.

Stewart added that he is optimistic the two sides will be able to work together, and he noted the Democratic primary helped cultivate thousands of grassroots supporters for Obama.

For now, the Obama campaign remains largely unassembled in Pennsylvania. According to Isenhour, campaign officials are still planning strategy for each state before putting staffers on the ground.

Stewart said six campaign staffers are criss-crossing the state urging grassroots groups to create registration drives.

Increasing those numbers still remains the campaign's goal for now, he said, because it was in Pennsylvania only four weeks before the state's registration deadline.