Melvin's victory shifts the political balance on the state's most powerful bench to Republican, and could portend a re-energized conservative base in the 2010 gubernatorial and congressional elections.

With 91 percent of ballots counted, Melvin had won every suburban county around Philadelphia except Montgomery, where Democrat Jack Panella of Easton led by only a few hundred votes.

"It's clear to me she won because of the wins in the Philadelphia suburbs, and that's something other Republican statewide candidates have not been able to do in recent years," said G. Terry Madonna, professor and pollster at Franklin and Marshall College.

Melvin, 53, a Superior Court judge from Allegheny County, and Panella, 54, a Superior Court judge from Northampton County, mounted costly campaigns that featured a particularly hostile TV advertising war in the final weeks.

Both candidates received high recommendations from the state bar association. Melvin collected endorsements from nearly every major newspaper.

Panella's campaign raised a record $2.35 million, outdoing Melvin by almost 3-1, according to statistics compiled by an advocacy group, Pennsylvanians for Modern Courts. He received about $500,000 each from unions and a Philadelphia trial lawyers' organization, the group said.

Melvin, who served 23 years as a judge on local, county and state courts, took in $30,000 in campaign funds from leaders of the Republican-controlled state Senate. Melvin's sister, Jane Orie, is a GOP Senate leader.

Lynn Marks, the Modern Courts group's executive director, said the amount of money in the race was troubling because much of it came from law firms, unions, and businesses that often litigate in state courts.

The vacancy on the seven-member court was created by the 2008 retirement of Chief Justice Ralph Cappy, who died this year. Gov. Rendell appointed Jane Cutler Greenspan to fill the seat until Cappy's 10-year term ended January 2010 with the understanding that she would not run for the office.

The election carries added significance this year because the high court will likely play a role in deciding how congressional and state legislative districts are reconfigured after the 2010 census. With two Republican and two Democratic appointees at the negotiating table, the court is empowered to choose the fifth, tie-breaking member of the reapportionment panel that oversees the redrawing of boundaries.

Madonna said the Melvin victory may well have been boosted by an strong Republican turnout, coupled with a large number of independent-minded women looking for a solid female candidate. But he cautioned against seeing the race as a bellwether for 2010.

"It was a much more energized Republican base that gave Republicans some enthusiasm in a state trending Democratic," the veteran pollster said. "But I wouldn't go overboard."