Why Would the Democrats Want Arlen Specter?

There really shouldn't be any way out of the political mess in which Arlen Specter finds himself. For decades, he's

There really shouldn't be any way out of the political mess in which Arlen Specter finds himself.

For decades, he's irked his party's conservative base with one high-profile apostasy after another. But he's also made sure to throw just enough bones their way to prevent an intraparty uprising from toppling him—as when he beat back, by a scant two points, a withering Republican primary challenge from Pat Toomey in 2004.

Now, though, his luck seems to have run out. The Republican base, nationally and in Specter's Pennsylvania, is shrinking and lurching ever rightward. Somehow, the right has convinced itself that the real lesson of the Democratic landslides of 2006 and 2008 is that the G.O.P. just wasn't conservative enough. Where there used to be at least some space for breaches of conservative orthodoxy, there is now none in the Republican Party.

In that sense, Specter sealed his own fate last month, when he essentially brokered the compromise that allowed President Obama's $787 billion stimulus package—pilloried by the right as a step toward socialism—to pass over a Republican filibuster in the Senate. At a public event shortly thereafter, a grateful Vice President Joe Biden showered praise on his old Senate colleague: "It might not help you, my saying this, but this legislation would not have happened without you."

That's an understatement. In the wake of the stimulus saga, Toomey, Specter's '04 G.O.P. challenger, has revisited his initial decision not to seek a rematch next year; now, he almost certainly will. Biden's praise will surely be recycled into a Toomey ad or two.

The forces that saved Specter in '04—a helpful Republican White House, a higher concentration of moderates within the G.O.P., and more tolerance for diverse views among conservatives (a luxury they feel they can no longer afford in the minority)—are now inoperative. The anger over his stimulus move is intense, and won't abate as long as the economy is struggling. Specter's poll standing among Pennsylvania Republicans is at an all-time low. It's easy to see Toomey's two-point defeat turning into a 20-point massacre next spring.

And that should be it for Specter, at least in theory: He can either go down swinging in a hopeless G.O.P. primary or acknowledge reality, announce that five terms is enough, and head off to retirement at age 80. Meanwhile, Pennsylvania's Democrats, who have lost Senate race after Senate race to Specter because his independent streak sits so well with swing voters, can lick their lips in anticipation of a general-election campaign against the far more beatable Toomey.

And yet, for some reason, Democrats are offering Specter a life preserver, in the form of inducements to switch parties and run as their candidate for another six-year term.

"We've tried—myself, Senator Casey, Vice President Biden," Pennsylvania's Democratic governor, Ed Rendell, said this week. "We've tried to talk him into it, but he's bound and determined to stay a Republican. He doesn't want to see Republican moderates vanish from the earth."

At a personal level, it's understandable why Rendell and Biden, who have long enjoyed cooperative and collegial relationships with Specter, would encourage him to join their team. (Presumably, Casey, who won his seat two years ago, enjoys a similar relationship.) But from a political standpoint, it's probably not in the Democratic Party's interest to convert Specter.

Granted, in the short term, a Specter switch—coupled with the seemingly inevitable seating of Minnesota's Al Franken—would give the Democrats the magic 60 Senate votes they've been craving. But 60 is just a number. There's really no reason to believe that Specter, even if he suddenly changed his registration, would morph into a party-line Democrat. Most likely, he'd be just as fickle and iconoclastic as he now is—hardly a reliable vote for every Democratic effort to end a filibuster.

Besides, why should Democrats settle for Specter, who would probably vote with the G.O.P. just as much as he votes with them, when they could very likely elect a far more reliable Democratic senator in '10?

Look at it this way: If Specter remains a Republican and battles it out with Toomey in a primary next year—his most likely course of action, at least for now—then Toomey will probably win and emerge as the G.O.P. nominee. Given his staunch conservatism, he'd make an ideal opponent for the Democratic nominee, who could paint Toomey as another Rick Santorum, who was drummed out of the Senate by Pennsylvanians in 2006.

But if Specter were to switch parties, the Republican nomination would be flung wide open. A more electable general-election candidate, one capable of navigating the conservative/moderate divide that Specter no longer can, might then emerge. Meanwhile, Democrats would face the prospect of an untidy primary, with Rendell and other party leaders (and interest groups, too: the A.F.L.-C.I.O. has promised to support Specter in a primary if he supports their "card check" legislation in the Senate) using their muscle on Specter's behalf while party activists push for their own candidate. Even if Specter were to win the Democratic nod without a fight, his general-election chances could be iffy—assuming Republicans picked a nominee other than Toomey.

The most politically advantageous posture for Democrats, it would seem, is to keep praising Specter but to stop begging him to join them. As long as tries to run for reelection as a Republican, the odds are good that the G.O.P. will nominate the supremely beatable Toomey. And if that's the case, Democrats might as well field a candidate who will side with them reliably in the Senate. Why Would the Democrats Want Arlen Specter?