After a career that's taken him through two parties, five terms, 30 years and thousands of votes, it was inevitable that the story of this Senate election would be all about Arlen.
What would have been harder to predict was the variety of Arlens it's been about -- the morphing Democrat-turned-Republican-turned-Democrat persona of Arlen Specter's own career shifts arrayed against the varied caricatures projected by a quartet of rivals.
There's the Arlen who's too liberal. Outraged by his positions on social issues, conservative activist Peg Luksik determined to run against the then-Republican at a time when it seemed that no one else would challenge him for the Republican nomination.
There's the Arlen who's too conservative. Rep. Joe Sestak, D-Delaware County, was poised to run against the Republican incumbent as well, challenging him from the left over his allegiance to the policies of the Bush administration. The former admiral had planned to meet the incumbent in the November election. The forum for their confrontation has shifted to the Democratic primary, but, defying the leadership of the party they now share, Mr. Sestak's criticism of the senator remains the same.
There's the Arlen who isn't as invulnerable as he once seemed. At a time when President Barack Obama and the Democratic congressional majority enjoyed considerably higher poll ratings, Pat Toomey, a former Republican congressman, was considering a run for governor. Then Mr. Specter, the man he had nearly ousted in the 2004 GOP primary, emerged as one of only three Republicans to support the administration's economic stimulus plan. That vote prompted Mr. Toomey to change his mind, renew his challenge to the veteran lawmaker and, consequently, drive him out of the Republican Party.
Finally, there's the Arlen who's too establishment. Joe Vod Varka, a Robinson machinist, is running in the Democratic primary not so much against Mr. Specter himself but against what he sees as the senator's membership in the broader political establishment out of touch with ordinary voters.
Mr. Specter's decision last April to return to the party of his youth shook state and national politics. It prompted widespread confident -- and wrong -- speculation that his move symbolized the end of competitiveness for the Republican Party in the Northeast. While he frankly acknowledged that he could not win a Republican primary against Mr. Toomey, polls then showed the incumbent with a solid lead in a general election in which the independents and Democrats he had always cultivated could vote.
But amid persistent high unemployment and eroding popularity for the administration, Mr. Toomey had by the fall moved ahead of both Mr. Specter and Mr. Sestak in the polls. In two more recent surveys, however, Mr. Specter had once again recorded narrow leads.
The election of Republican Gov. Chris Christie in New Jersey and the come-from-behind upset by Sen. Scott Brown in Massachusetts brought vivid evidence that the reports of the death of Republican chances in the Northeast were greatly exaggerated.
When he crossed the Senate aisle, Mr. Specter gave Democrats a filibuster-proof majority. Mr. Brown took that away. At this point, no handicapper predicts that this year's Senate elections will restore such a super-majority to the Democrats.
But that has not cooled the loyalty of the Democratic establishment for their new member. Mr. Obama, Vice President Joe Biden and numerous Cabinet members have paraded through the state with him over the past year. Gov. Ed Rendell has enthusiastically thrown his support behind his old friend and Philadelphia neighbor. In a recent meeting of the Democratic State Committee, Mr. Specter crushed Mr. Sestak in the party officials' endorsement vote. And last week, state AFL-CIO officials produced a two-thirds majority to add their endorsement.
The senator isn't resting on the value of high-profile endorsements. He has campaigned relentlessly across the state, making return visits to each of the state's 67 counties since September.
"I'm the founding member of the 67 Club," he boasted Friday as he headed into a Lawrence County breakfast where several of the assembled Democrats greeted him with reminders of past encounters.
Richard Christofer, the Lawrence County Democratic chairman and former mayor of New Castle, gave Mr. Specter an enthusiastic welcome along with a reminder of past meetings discussing local projects for the economically challenged region.
"I've always supported him," Mr. Christofer said.
Mr. Specter has easily outdistanced his chief Democratic challenger in every public poll so far. But Mr. Sestak contends that a large undecided vote translates into a dynamic race. The most recent poll from Quinnipiac University showed Mr. Specter leading Mr. Sestak, 53 percent to 29 percent, with 14 percent undecided. The Franklin and Marshall College poll, however, found a race last month in which Mr. Specter was leading Mr. Sestak, 32 percent to 12 percent, with a whopping 52 percent undecided.
"A verdict has already been made about that 30-year incumbent, former Republican in that there are so many undecided out there," Mr. Sestak argued last week.
He alluded to the rule-of-thumb in polling that undecided voters break disproportionately against a well-known incumbent.
But the Specter campaign is intent on making sure that the 2010 election is not just a referendum on the incumbent. That was evident in the first ad of this campaign, aired more than a year ago, when Mr. Specter -- then still anticipating a GOP primary matchup against Mr. Toomey -- sought to introduce the little-known former congressman as a Wall Street manipulator mired in trading practices that produced the economic meltdown.
The campaign had to amend the ad because it accused Mr. Toomey of trading financial products that didn't exist during his time as an investment banker. But if the facts of the ad were clouded, its tactical approach was clear.
The incumbent's campaign has similarly sought to keep its chief Democratic challenger on the defensive, pointing out repeatedly that Mr. Sestak has missed more House votes than any member of the state's congressional delegation. The campaign also has criticized Mr. Sestak over the fact that many of his staff members are paid less than the minimum wage.
"Is there anything more fundamental in America than the minimum wage?" Mr. Specter demanded Friday as he skewered his challenger at the Lawrence County breakfast.
Mr. Sestak contends that those criticisms are efforts to distract voters from his own indictment of Mr. Specter's long record and recent political conversion.
"People are really ready for change," he said. "They're tired of Washington politics as usual and, frankly, Arlen is a symbol of that."
Mr. Sestak has traveled the state hammering at the incumbent for his votes in favor of former President George W. Bush's budgets and tax cuts.
"He's voted almost lock step with Rick Santorum and Pat Toomey," he said. "And now he's a Democrat?"
Polls show that most Democrats in the state haven't heard enough about Mr. Sestak to express an opinion. But his campaign has the money to change that and to amplify his critique of the incumbent through the crucial megaphone of television ads.
"We are right where we want to be, maybe a little ahead," he insisted in an interview last week.
Mr. Specter has the larger war chest. He started the year with nearly $9 million in cash on hand. Mr. Sestak had more than $5 million at the same point, guaranteeing that he will be able to have a significant presence on television.
Mr. Vod Varka's shoestring campaign has no such resources, but he does have at least the potential to represent a problem for Mr. Sestak, as a competitor for anti-Specter votes, which explains why the Sestak campaign is challenging Mr. Vod Varka's nominating petitions in Commonwealth Court.
The Toomey challenge to Mr. Specter was a defining influence in the overall Senate race, but since Mr. Specter's decision to switch parties, the Republican side of the race has received less attention than the primary of the senator's new party. That's because of the perception that the GOP contest is less competitive. Mr. Toomey has been seen as the prohibitive favorite in that primary ever since he spurred Mr. Specter's flight from the GOP.
No public poll has even bothered to test Mrs. Luksik's name in a trial heat this year. The handful that did in the spring and summer of 2009 found her candidacy mired in low single digits. The conservative activist, a veteran of three runs for governor in two parties, scoffs at such projections. Mrs. Luksik contends that a network of grassroots supporters will bring her under-the-radar candidacy within striking distance of the GOP nomination.
In particular, Mrs. Luksik holds herself out as the truer champion of the crusade against abortion rights. Mr. Toomey also opposes abortion rights, but his position has evolved since his first congressional campaign when he offered qualified support for abortion rights.
Mrs. Luksik calls for a smaller government and says one of her prime goals in office would be to enhance the role of the family in contrast to a society in which she sees a growing federal government supplanting the family.
While his campaign reaches out to social conservatives, Mr. Toomey placed a greater priority on economic issues through his three terms in Congress representing a Lehigh County district. Later, he was chairman of the anti-tax Club for Growth. In 2004, he narrowly missed ending Mr. Specter's Senate career in a primary in which the energetic support of senior Republicans such as President Bush and Sen. Rick Santorum helped the incumbent prevail, 51 percent to 49 percent.
Mr. Toomey's recent rise in the polls came in a year that also saw the emergence of outspoken, angry conservative forces such as the tea party and 9.12 groups. His stands on most issues would be welcome to such audiences, but his tone isn't as confrontational as some voices in his party.
He has criticized the Obama administration unrelentingly on issues such as health care and the spending in the stimulus package. But in contrast to many Republicans, he has seemed to look for areas of common ground with the president.
Last year, when some GOP figures portrayed Mr. Obama's recorded message to the nation's school children as an ominous attempt at left-wing indoctrination, Mr. Toomey called it inspirational. He also called for the confirmation of Justice Sonia Sotomayor.
More recently, he voiced support for a presidential initiative to support exports. He also has projected this civil face for strict conservatism in an informal debate, followed by a shared beer with Mr. Sestak in September.
But that nice-guy offensive hasn't softened his overall indictment of the administration or of the candidate he hopes to take on in the fall. While he's acknowledged that the president can give an "inspiring" speech, he also says that his polices are geared to the creation of "a European-style welfare state."
Politics Editor James O'Toole: firstname.lastname@example.org or 412-263-1562.