Specter was raised in Depression-era Kansas. In the small town of Russell, he worked many afternoons in his father's junkyard at the sweaty, backbreaking task of unloading scrap metal from trucks and railroad cars. For his father Harry, a Jewish immigrant from Ukraine, the thriving business during World War II was a step up from peddling blankets and cantaloupes door-to-door, and allowed him to send his four children to college.
Specter graduated from the University of Pennsylvania in Philadelphia, where his father had relatives. After earning a law degree at Yale, he began his public service in 1959 as an assistant city district attorney.
In his 2000 book, "Passion for Truth," he noted how his father had complained bitterly that the U.S. government had broken its promise to pay a bonus to World War I veterans.
"Figuratively, " he wrote, "I have been on my way to Washington ever since, to get my father's bonus."
He made his name sending six Teamsters' officials to prison for conspiracy to misuse union dues, a victory noticed by U.S. Attorney General Robert F. Kennedy. It helped pave the way for Specter's service as a staff lawyer on the Warren Commission investigating the assassination of President John F. Kennedy.
He became known as the architect of the "single-bullet theory" that buttressed the finding that Lee Harvey Oswald was the lone assassin. Although it has withstood the test of time, the theory was considered by some — and depicted by director Oliver Stone's 1991 film "JFK" — as a magic-bullet concoction designed to cover up a perceived right-wing conspiracy.
Specter wanted next to run for DA, but city Democratic Party leaders didn't have him in their plans. So he became a party-switcher for the first time, running successfully on the Republican ticket in 1965 against his former boss.
He lost the 1967 race for mayor and was defeated in the 1973 DA's race.
He lost the GOP Senate primary in 1976 and the GOP gubernatorial primary in 1978 before winning Pennsylvania's open U.S. Senate seat in 1980 amid the tide of Republicans who took control of the Senate along with Ronald Reagan's presidential election.
Initially, he was part of a robust group of centrist Republicans. As time wore on, and the Republican Party shifted to the right, he became increasingly isolated.
Unapologetic about his political centrism or his Jewish heritage, his positions — such as support for abortion rights or his opposition to a constitutional amendment to reinstate school prayer — often put him at odds with much of the Republican Party.
His terse comebacks, sharp wit and relentless pursuit earned him the nickname "Snarlin' Arlen."
He is perhaps best-known for his role in Supreme Court confirmations — he took part in 14 hearings, he said — because of his long service on the Judiciary Committee and his dogged questioning.
Often, he sought a nominee's assurances that they would give proper weight to legal precedent — the body of law developed through more than a century of Supreme Court decisions.
He helped sink Reagan's 1987 nomination of Robert H. Bork, calling him a "throwback" who would help outlaw abortion.
And in 1991 he earned the enduring anger of many Democrats — and a tough re-election challenge a year later — when he aggressively questioned the honesty of Anita Hill, a law professor who had accused Supreme Court nominee Clarence Thomas of sexual harassment.
His political centrism forced presidents, colleagues and lobbyists to pursue his vote with extra vigor. At times, it infuriated liberals: The Senate's Democratic majority leader, Harry Reid, wrote in his 2009 book that Specter "is always there when we don't need him."
On the other hand, Reid spoke glowingly about Specter from the Senate floor in April on the one-year anniversary of Specter's party switch.
"I have never seen another senator with a greater willingness to work in a bipartisan manner, to put people over party and encourage others to search their hearts and do what is right," Reid said.
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