IF THERE were a political version of the popular game of Twister - the one that rewards the best contortionist - then Specter would be its all-time champ.
In the end, it was "left foot, blue" that caused him to fall.
En route to becoming the longest-serving U.S. senator in Pennsylvania history over three remarkable decades, Specter had to beat Philadelphia's Democratic machine by becoming a Republican, find new life after Watergate in the Reagan Revolution, infuriate conservatives with one Supreme Court vote and liberals with another, and overcome "The Year of the Woman."
But for a politician who successfully changed course so many times, the marble-voiced 80-year-old wasn't able to tack one last time into the stiff political winds of 2010. Specter learned that changing parties isn't a solution for a centrist in a world where the media and primary voters are highly partisan and ideological.
Specter's stunning defeat yesterday - at the hands of a hard-charging ex-admiral, Rep. Joe Sestak, and of liberal Democratic primary voters put off by Specter's long life in the GOP - was clearly another sign that his middle-of-the-road political bent was a relic of an earlier time.
The reason he lasted in Pennsylvania this long was ideology.
Simply put, he didn't have one.
"Arlen was always about getting things done," said Philadelphia power lawyer Arthur Makadon, one of a bevy of ambitious young district attorneys that Specter hired in the 1960s, who saw his ex-boss as neither a man of the right nor the left.
Indeed, throughout his long run, Specter seemed driven by three things: Bringing tangible benefits home to Pennsylvania; following the rule of law, which led to some outside-the-box political moves (like his Scottish law "not proven" impeachment vote for Bill Clinton); and advancing his career.
Maybe Specter was destined to be different. Born at the dawn of the Great Depression on Feb. 12, 1930, Specter - whose Russian emigre dad was a tailor and junkyard owner - was part of the only Jewish family in Russell, Kansas, the small town that also produced his future Senate colleague Bob Dole.
His future was altered when he transferred to the University of Pennsylvania; he married Joan Levy, later a city councilwoman, and, after graduating from Yale Law School, came back to Philadelphia to raise two kids .
A hard-charging young attorney who made friends in high places - including Attorney General Robert Kennedy - by investigating corrupt Teamsters, Specter was called to Washington in 1964 to join the Warren Commission probing the John F. Kennedy assassination.
It was there that Specter first gained fame - or infamy, depending on your perspective - when he was assigned to lead the probe of alleged assassin Lee Harvey Oswald and came up with the "single-bullet theory" to explain multiple wounds suffered by JFK and Texas Gov. John Connolly.
"Because the bullet hit two different people, it was hard to say that there wasn't a second guy involved," later transportation secretary William Coleman, who worked with the commission, told Philadelphia magazine. "He was the one to demonstrate to [commission head Earl Warren] that there was only one bullet; it went through both of them."
Years later, his role was ridiculed in Oliver Stone's movie "JFK," but Specter's local stature grew, and in 1965 the ambitious 35-year-old was ready to run for Philadelphia district attorney. But the ward-dominated Democratic machine of Mayor James Tate wasn't ready for him.
So, Specter set his partisan odyssey into motion by becoming a Republican. He won for D.A., barely lost to Tate for mayor in 1967, when he wouldn't pledge to rehire controversial top cop Frank Rizzo and was re-elected D.A. in 1969 with GOP controller Tom Gola on the famous slogan: "They're younger, they're tougher, and nobody owns them."
Still, a scandal cost Specter his job in 1973 - not his scandal, but Richard Nixon's, which was Watergate. He wandered in the political wilderness, losing elections for governor and U.S. Senate, and was laughed off in 1980, when he ran again for the Senate, only to sweep in on Ronald Reagan's coattails.
After those years and into his Senate career, Specter was often compared to the Woody Allen movie character "Zelig," for his bizarre knack of showing up at historic moments. Even as a defense lawyer out of politics in the late 1970s, he showed up representing "hippie guru" killer Ira Einhorn when Einhorn skipped town for France. He also became known as a tough boss, with a high rate of staff turnover.
His politics were harder to pin down. His defining moment in Washington may have come in 1987, when he aggressively grilled the Supreme Court pick of his own party, Reagan nominee Robert Bork, and then opposed him as too conservative. His actions set the stage for the contentious judicial-nomination fights that have lasted to this day
But just four years later, he became a pit bull in favor of a conservative Republican court pick, Clarence Thomas - infuriating liberals with his prosecutorial grilling of Thomas' sexual-harassment accuser, Anita Hill. The backlash, led by female Democratic newcomer Lynn Yeakel, almost cost Specter his seat in 1992, the so-called "Year of the Woman."
Specter watchers say that the senator pushed so hard for Thomas for one reason - the GOP brass asked him to, and his enthusiastic response was part of his political-survival instinct.
"He was asked by his party leadership to do it," said G. Terry Madonna, the Franklin & Marshall College political scientist and pollster, adding that "after Bork, maybe he was currying favor with the Republicans because he was up for re-election in 1992."
The Anita Hill episode revealed something else about Specter's career: that he was always most comfortable playing the role of prosecutor. A by-product was that Specter was a strong supporter of civil liberties, even in an era when the ACLU (American Civil Liberties Union) was a dirty word in GOP circles. During the George W. Bush years, he bucked the White House on warrantless wiretapping.
In an era when American politics grew more bitterly ideological, Specter became almost aggressively centrist. He announced in 1995 that he would run for president, saying that Republicans should not be "so captive to the demands of the intolerant right that we end up re-electing a president of the incompetent left." He dropped out before a single vote was cast.
Increasingly, Specter - a tireless traveler to the state's 67 counties - focused on the non-ideological job of bringing money and projects back to Pennsylvania.
A cancer survivor, the senator's lasting legacy may be the billions that he sought and received for the National Institutes of Health and other medical programs, while breaking with social conservatives on the need for stem-cell research.
"He always put Pennsylvania first, and delivered for Pennsylvanians," said Larry Ceisler, a Philadelphia political consultant - but, oddly enough, that mission sowed the seeds of his political demise.
When Specter crossed party lines early last year to support President Obama and his $800 billion stimulus plan that meant tens of millions of dollars for Pennsylvania, the right-wing backlash was so loud, it was clear that he couldn't beat GOP conservative Pat Toomey, who'd almost toppled him in 2004. With support from Obama and his lifelong friend and now-governor, Ed Rendell, he bolted to the Democrats.
But his political gyrations - campaigning before the cameras in 2004 with Bush and right-wing icon Rick Santorum - were just too much for the more ideologically blue, left-leaning voters in yesterday's Democratic primary.
They forced the retirement day that Specter hoped never to see.