All Sen. Arlen Specter wants as he sits down at the Vietnam Georgetown Restaurant after a bruising day of fighting for survival is a gin martini, with olives. How hard is that?

"Bartender is not here tonight. No mixed drinks - beer, wine only," the young waiter says, tapping a pencil on his order pad.

"No bartender?" Specter says. "How about a manager?"

The kid shakes his head. "Well, how about straight gin on ice? Can you do that?" Specter asks, sighing. The waiter is puzzled. "Straight gin," Specter repeats, exasperated now. Ah, the kid realizes, this customer is not going to take no for an answer.

"It's ridiculous, not having a bartender. What's this?" Specter grumbles as the waiter darts off to fetch the gin. "I guess I'll have to go home and make my own martinis." Rrrr.

On this evening last spring, Specter, 79, was under siege. Not long before, he had been one of three Republican senators whose votes had enacted President Obama's $787 billion economic stimulus, and the blowback was fierce. To the GOP base, that program was the very worst in bloated government spending, something that, piled atop all the bank bailouts, would just drive up the deficit and expand government's control of the economy.

Specter was branded a traitor, a weasel - and not for the first time. It seemed that all the years of compromises and deals, of taking the middle path, had caught up to him. The Republican State Committee at its winter meeting considered a censure resolution. People picketed his Allentown office. A conservative former U.S. representative, Pat Toomey, prepared to abandon his exploratory campaign for governor of Pennsylvania to take another shot at Specter. Toomey had come within 17,000 votes (out of more than one million cast) of ending Specter's Senate career in the 2004 Republican primary. Citing polls, firebrands urged Toomey to finish the job.

Specter was treated on cable news and in newspapers like some exotic zoo animal - the endangered moderate Republican. Now that he had stepped on the stimulus mine, other tricky votes were coming up, on union rights and health care, for instance. Conventional wisdom held that he was toast. Maybe he would finally jump to the Democrats?

No, Specter insisted, never.

Yet weeks later, that's exactly what he did.

His bruising ballet

During the next seven months, Specter would dance to salvage all he had built over a lifetime, the power to nudge federal law toward his vision of precision, to endow lifesaving biomedical research nationwide, and to bring federal projects to his state.

The public ballet would spotlight character traits that have made Specter such a towering figure over five decades: grit, boldness (and its twin, opportunism), abrasiveness, intellect, a fierce love of verbal combat.

It may be his hardest act yet, but if one characteristic defines Specter's career and life, it is this: Nothing comes easy. Indeed, after he became a Democrat in April to avoid one primary challenge from the right, he found another threat on his left in the pesky form of Rep. Joe Sestak, who hammers Specter as an insincere Democrat and implies he is too old.

Specter has served in the Senate longer than anyone in Pennsylvania history, a milestone that would have seemed laughable when he was losing races for district attorney of Philadelphia, mayor, governor, and U.S. Senate. In 1980, he butted his head against the wall again and eked out a win by 2 percentage points. His secret weapon: visiting every wide spot in the road in all 67 counties, pushing, pushing, pushing.

And he has survived illnesses that might have daunted a less determined man: two bouts of Hodgkin's lymphoma and the brutal chemotherapy that knocked down the disease, open-heart surgery, a benign brain tumor.

At dinner, Specter eats a forkful of salmon, then gulps a glass of water.

"You bite into one of those peppercorns," he says, "you're in trouble."

Hard to fathom

It seems we have always known him and yet we do not really know him at all.

Arlen Specter has been around so long, influenced so much of the modern history of Philadelphia and the nation, that his image is imprinted on miles of videotape, hundreds of thousands of yellowing newspaper clippings, and two volumes of autobiography.

Who he is underneath he keeps to himself.

Jowly, his face like a basset hound's, Specter is not a natural politician. His public smile is tight, as if willed into place. He often seems in a hurry to get somewhere else. And even after a lifetime away, he retains the barbed-wire prairie accent of his Kansas boyhood.

Specter loves to tell stories, his favorite ones polished smooth as riverbed stones, and he's wickedly funny. Just don't ask him to disclose his feelings, discuss motivations, or analyze his career.

He professes to be unconcerned with how history will categorize him.