Here was one candidate, they said - a moderate, a maverick - who might win back a county that long has been dominated by Republicans on the local level but that has voted Democratic in the last four presidential elections.

Now this Republican hope is being tested from Ridley Park to Media to Springfield - and across the Philadelphia suburbs - amid an economic gloom that polls suggest may be a drag on McCain's chances.

"I'm just sick - sick of everything," said Nick Guacci, 60, of Prospect Park, a Republican who is wavering between voting for McCain or Democratic Illinois Sen. Barack Obama.

A retired plumber, he said he liked McCain but held Republicans responsible for the Wall Street tumble that threatens his 401(k) savings plan. He jokingly derided Obama as "Osama," but said he may vote for him to get Republicans out of the White House.

Another Republican retiree, Francis Rosenstiehl of Essington said Obama wasn't experienced enough to be president. But he thinks that McCain, at 71, is too old. He said that if McCain's running mate, Alaska Gov. Sarah Palin, became president, she wouldn't be up to handling an economic crisis: "I don't want to see that lady take over.

"I'm still undecided," he said, "but I think I'm going to go with the Big O."

How many Republicans and independents think as Guacci and Rosenstiehl do may determine the outcome Nov. 4 in the key state of Pennsylvania.

Democrats have made huge gains since 2004 in voter registration, going from 34 percent of the county electorate to 42 percent. Together with independents, they now outnumber Republicans, who have 48 percent of registrants.

McCain clearly must improve on President Bush's track record. Bush lost three of Philadelphia's four Pennsylvania suburban counties - all but Chester County. In Delaware County in 2000, he lost to former Vice President Al Gore by 12 percentage points. In 2004, he lost to John Kerry by 15 points.

James E. Vike, associate professor of government and politics at Widener University, said that if Obama can't take the suburbs, where even many Republicans have more liberal social views than voters elsewhere, it would be "a bad sign for his potential across the state."

Several independent polls conducted by colleges and universities show Obama opening up a statewide lead of anywhere from 7 to 15 points.

Berwood A. Yost, director of opinion research at Franklin and Marshall College, said that voters who name the economy as their No. 1 issue prefer Obama over McCain by 53 percent to 29 percent.

"That's what is driving the vote, I think," Yost said.

Delaware County - with its mix of Main Line affluence, working-class struggle along the Delaware River, and middle-class aspiration in between - presents an interesting case study in the battle for suburbia.

Its history is Republican, top to bottom.

In the 1920s, the county's eastern boroughs and townships were filled with people taking advantage of the trolley lines running out of Philadelphia.

Philadelphia was then a Republican bastion, and the arrivals brought Republican affiliation with them. Decades later, when the city turned Democratic, the county remained true to the GOP.

This was a far different GOP from other suburban counties. It was blue collar, not white collar; rowhouse, not manor house.

Today, much of Delaware County retains its blue-collar character, which could be a boon to McCain. A national survey by the Pew Research Center for the People & the Press found that white residents with a high school education preferred McCain by large margins.