Pennsylvanians yesterday mourned Massachusetts Democratic Sen. Edward Kennedy amid memories of a 1980 primary campaign that was the high-water mark of his presidential ambitions, but only a prelude to the lofty plane of influence that the senator would occupy for decades to come.

Mr. Kennedy came into Pennsylvania after a string of defeats in his quest to wrest the Democratic nomination from then-President Jimmy Carter. Considering a Kennedy challenge, Mr. Carter had once promised to "whip his ass" and seemed to make good on the threat through the early spring, winning 10 of 13 earlier primaries.

Pennsylvania loomed as one of the last big-state opportunities for the Massachusetts senator to blunt the incumbent's momentum. Until last year's epic primary battle between Democrats Barack Obama and Hillary Rodham Clinton, the 1980 contest -- with a complementary GOP battle between two future presidents, George H.W. Bush and Ronald Reagan -- would be the last really significant Pennsylvania primary.

"I can remember one of the biggest outdoor crowds I ever saw was behind the William Penn [hotel]," Judge Thomas Flaherty recalled of an early rally for the insurgent Democrat. "They closed the street, and that huge crowd went over way into the park."

Mr. Flaherty, then a Pittsburgh City Council member, would go on to be a Kennedy delegate at the Democratic National Convention. He was in a minority among the local party establishment in backing him.

Across the state, a future governor, Ed Rendell, was also among early backers of Mr. Kennedy. In a statement released yesterday, the governor called him one of the nation's greatest statesmen of all time. "I will miss him as a friend, and the nation will miss him for the leadership, the guidance and the love that he gave to all of us," Mr. Rendell said.

The governor hailed from the region that would provide the foundation of what would be a narrow Kennedy victory here. In his survey of presidential politics in the state, "Pivotal Pennsylvania," Franklin & Marshall College scholar Terry Madonna said the key to Mr. Kennedy's primary victory was support from the Philadelphia Democratic organization, led by then-Mayor William J. Green III.

Mr. Kennedy won only nine of the state's 67 counties, but they were enough for a narrow overall victory, with 46.2 percent of the Democratic votes, compared with 45.6 percent for Mr. Carter -- a difference of fewer than 5,000 votes.

Philadelphia and the state's northeast corner produced big numbers for Mr. Kennedy, but he trailed elsewhere -- losing in Allegheny County, then the state's second-largest Democratic stronghold.

Mr. Madonna noted that exit polls showed that voters most concerned about the lagging, inflation-worn economy were more likely to vote for Mr. Kennedy, who had campaigned relentlessly in the state.

Mr. Carter did not make any personal campaign appearances, citing demands of the ongoing Iranian hostage crisis, but his campaign commercials tacitly invoked the accidental death of a Pennsylvanian who had drowned in Mr. Kennedy's car, Mary Jo Kopechne, as the ads stressed character issues in the campaign's final days. Exit polls showed that Carter voters were more likely to cite character as the issue determining their choice.

Mr. Kennedy's narrow Pennsylvania victory gave him an edge of only a single delegate -- he won 93, while Mr. Carter held onto 92. The bare advantage was not enough to sidetrack the incumbent's momentum.

Dr. Cyril H. Wecht was Allegheny County's Democratic chairman for that election. He recalls the convention controversy over a Kennedy proposal to have both candidates release their delegates, but said he tried to remain neutral because of his party position. "I couldn't give orders ex cathedra; I tried to keep an open mind," he said of the convention controversy.

Mr. Rendell, Mr. Flaherty and Mr. Wecht were all on the convention floor to hear Mr. Kennedy's memorable "The Dream Will Never Die" concession speech, which set off a protracted demonstration that exceeded in emotional power the winner's reception.

For Kennedy partisans, it was bittersweet, seemingly closing the senator's bid for ultimate political power. "It was the greatest speech I ever heard in person," Mr. Flaherty said.

But as numerous eulogists have noted, that primary defeat was the prelude to Mr. Kennedy's greatest period of influence, as one of the most powerful members of the Senate in decades to come -- an assessment shared across partisan aisles yesterday.

Veteran Senate colleague Arlen Specter of Pennsylvania, now a Democrat but for most of those decades a Republican, said: "Sen. Kennedy made historic contributions on civil rights, health care, education, the judiciary, labor law, immigration and virtually all facets of life in America. Working with him on the big issues of our era was a real privilege."

Sen. Bob Casey recalled Mr. Kennedy's legacy on a host of issues, including the children's health care legislation that was one of the Pennsylvania junior senator's key priorities, as it had been for his father, the late Gov. Robert Casey.

"You saw on that bill a couple of features that made him maybe the most effective senator of the last century," Mr. Casey said. "It showed his passionate advocacy for children and, two, it showed how effective he could be in work with Republicans. ... Republican senators would tell you that there's no senator they worked with more effectively, who was more patient in listening to their point of view."

Mr. Casey said Mr. Kennedy's recent Senate absence because of his own health was one more challenge to achieving consensus on legislation for national health care reform. Asked if the Massachusetts senator might have changed the debate's tone, he replied: "Without a doubt."

"His physical presence in Washington was really missed," Mr. Casey said. "... [W]e'd probably be further down the road. ... It's hard to quantify ... the nature of his ability and his leadership in getting people to work with one another."

Despite their sharply contrasting ideologies, former Pennsylvania Sen. Rick Santorum said of Mr. Kennedy, "I respected him as an incredibly skilled senator and unbending fighter for the most liberal of causes that he believed would benefit our country.

"When he was out of the arena, he was an affable colleague who was fun to be around," Mr. Santorum added. "On a personal note, I will always warmly remember in October of 1996 that he was the first of my Senate colleagues to call me and express his condolences for the loss of our son Gabriel."

Pittsburgh Steelers owner Dan Rooney, now U.S. ambassador to Ireland, lauded Mr. Kennedy for his contribution to the nation of their ancestry as well as to his own. "Since his early days in the Senate, Ted Kennedy was active in the Northern Ireland peace process," he said. "He introduced resolutions condemning all violence in Northern Ireland, expressing support for the Good Friday agreement in 1998 and the blueprint for lasting peace."