Arlen Specter was remembered nationally for his bipartisanship and long career as a statesman as news spread Sunday that the former U.S. senator had died of cancer at 82.

From President Obama to a former Eagles wide receiver, dignitaries voiced admiration for the man who, despite an often gruff demeanor, became Pennsylvania's longest-serving U.S. senator by forging compromises.

In an interview Sunday, U.S. Sen. Bob Casey told a highly personal story from 2002, when he lost the Democratic primary for governor to Ed Rendell. Specter, he said, called to commiserate.

"He had been through some tough primary defeats himself over the years, and he said I should keep my head up, I'd get another chance," Casey said. "I was grateful. Sometimes when you lose, nobody calls."

Specter, then a Republican, was also gracious to Democrat Casey when he was elected to the Senate in 2006. Casey said Specter invited him to lunch in the Senate dining room not long after the election.

"He said to me something I'll never forget: 'It's important to work together when we can, and it's important for people to see us working together.' "

At a get-out-the-vote appearance in West Philadelphia Sunday, the Rev. Jesse Jackson expressed sadness and condolences to the Specter family. A Democrat whose national prominence grew during the years when Specter's own power and profile rose, Jackson said he and the former senator shared an ultimate respect for democracy.

"Arlen Specter was a man of immense dignity and vision whose politics was not limited to the party," Jackson said. "He stood alone as a man and a voice of conscience.

"He did not limit his sense of justice to party politics. He chose the republic over Republicans, and democracy over Democrats."

Only minutes after Specter's family announced that he had died at 11:39 a.m., a fellow Republican whose career has included bipartisan stands, U.S. Sen. John McCain (R., Ariz.), issued this statement on his Twitter account, @SenJohnMcCain:

"Arlen Specter - a dear friend who served his state and nation with honor and distinction. RIP."

U.S. Sen. Pat Toomey, a more ideological Republican who unsuccessfully challenged Specter in a 2004 primary, issued a statement calling his predecessor "a man of sharp intelligence and dogged determination. . . . His impact on our state and public policy will not be forgotten."

U.S. Rep. Pat Meehan (R., Pa.) likewise praised Specter, saying in a statement that he had "made tremendous and long-lived contributions to Pennsylvania and to our nation" and "attacked problems and sought to find consensus for solutions."

"Pennsylvania has lost a political figure whose career stretched from Philadelphia's City Hall to the chambers of the U.S. Senate. We are saddened to hear of his death," Gov. Corbett, a Republican, said in a statement.

Former Republican Gov. Tom Ridge said in an interview he would remember Specter for three things: "His unapologetic independence, his steadfastness in what he believed was right, and his tireless campaigning.

"He worked all 67 counties in the state like they were a congressional district," said Ridge, a six-term congressman from Erie before he was governor. "It was like his oxygen. He actually liked doing it. I don't know anyone who worked that hard."

"Sen. Arlen Specter was a great man and a great public servant," said Mayor Nutter, a Democrat. "His door and resources were always open and available to virtually any request I made on behalf of the city."

"Arlen Specter was a political giant and a Philadelphia institution. His passage is a tremendous loss to this city and to American politics, which could use a thousand more like him," City Council President Darrell L. Clarke, a Democrat, said in a statement. "Democrat or Republican, anything you needed, you called Arlen Specter." He added that Specter had never forgotten his Philadelphia roots and "might have been the greatest sports fan our region has ever seen."

In a Tweet @DonteStallworth posted at 1:01 p.m., former Eagles wide receiver Donté Stallworth wrote: "Damn - Senator Arlen Specter passed? RIP my friend."

"From the committee room to the Senate chamber, Sen. Specter offered a voice of reason and passion in every debate - always willing to reach across the aisle and work across party lines to get the job done, regardless of political gamesmanship or gain.," U.S. House Minority Leader Nancy Pelosi (D., Calif.) said in a statement.

Robert Reich, secretary of labor in the administration of former President Bill Clinton and a man whose liberal convictions are a hallmark of his policy work, issued this Tweet @RBReich:

"Arlen Specter spoke his mind and his conscience. A principled conservative. One of the last of his breed."

"You rarely meet a man with the character and strength of conviction Arlen Specter had," Charles Kopp, a Center City lawyer and Republican powerbroker, said of his friend of four decades: "He either had a strong view or no view - nothing halfway."

He recalled a lunch with Specter in December 2002, just before the senator was to hold a news conference to defend then-Senate Majority Leader Trent Lott, Republican of Mississippi, who was under fire for saying the nation would have fewer problems if it had elected Strom Thurmond, who ran for president as a segregationist in 1948.

"Arlen said he thought that Trent Lott was getting a bum rap, that he was a good man," Kopp said. "I told him that supporting him was probably not the wisest thing to do politically. He was facing a freight train at that point, and he didn't have to do it. He said, 'I know, but it's what I believe.' "

Contact Maria Panaritis at 215-854-2431, mpanaritis@phillynews.com, or follow @panaritism on Twitter.

Inquuirer staff writers Angela Couloumbis and Jonathan Tamari contributed to this article.