By Albert R. Hunt

Democrats are rejoicing that Sen. Arlen Specter is praising Supreme Court nominee Sonia Sotomayor as proof of their wisdom in persuading him to defect from the Republican Party.

Specter has snookered them once again. In his five terms, he has voted for 10 Supreme Court nominees, opposing only Robert Bork. He would have backed Sotomayor whether he was a Democrat, a Republican, or a Scottish Whig.

The much-heralded Specter conversion, bringing Democrats close to the 60 votes required to break a filibuster, is a pyrrhic victory. Politicians, like companies, usually suffer when they focus on short-term gain. The lure of party-switching is always greater than the reality, and in a way the episode illustrates why Pennsylvania is a graveyard for anyone with national aspirations.

Specter's own calculations were that he would have lost a Republican primary against a conservative challenger he barely beat six years ago. If President Obama's political team, Democratic Senate campaign chairman Robert Menendez of New Jersey, and Gov. Rendell had actively enlisted a solid Democratic candidate months ago, he or she would have been a prohibitive favorite to win a general election.

Instead, Specter may struggle in a bitter Democratic primary next year against Rep. Joseph Sestak, a retired Navy admiral. If Specter wins, he'll be 80 years old, beset with health problems, and, as always, cantankerous.

"The Democrats could have gotten a 100 percent Obama Democrat," said Terry Madonna, director of the Center for Politics and Public Affairs at Franklin & Marshall College. "Instead, they'll have a 50 percent Obama Democrat, which is the best Specter will be."

A new Democratic senator would have been a generation or two younger than Specter. If the incumbent does win and faces health problems, a new Republican governor could end up appointing a member of his own party to the seat.

Yet the White House, Senate Democrats, and Rendell, practicing the politics of yesterday, are vowing to go all out for Specter. They insist he will deliver more pork for the state and be a major player in advancing the Obama agenda.

The latter point seems fanciful. Specter was one of three Republicans who voted for the stimulus. Yet he never was going to vote against high-court nominees or the other filibuster-driven issue, health-care reform, which he made a priority after his battles with cancer.

Democrats control the Senate 59-40 and likely will gain another seat from Minnesota. That doesn't much change the filibuster dynamics. To get 60 votes for anything would require the support of conservative Democrats or moderate Republicans. It will surprise many if Specter provides the 60th vote on more than one or two issues in this Congress.

The White House and some Democratic strategists say his switch will encourage others to convert. If there's a stampede, it's been a silent one. The growth of American political parties occurs from the grassroots up or when a national figure galvanizes support, not when a handful of elected officials change parties.

In the 1980s, celebrated party-switchers were supposed to usher in a whole new era of Ronald Reagan Democrats. Former Rep. Phil Gramm of Texas was the most successful. He ultimately cratered.

In the mid-'90s, when Democratic Sens. Richard Shelby of Alabama and Ben Nighthorse Campbell of Colorado became Republicans, it was heralded as a harbinger of realignment. Campbell disappeared, and Shelby is still in the Senate, in the GOP minority.

Specter switched for one reason: survival. It had nothing to do with principles, loyalties, or a change in philosophy. He will accommodate the exigencies of the moment, while relying on a political system in Pennsylvania that rewards such behavior. The last time this populous state produced a truly national politician was a century and a half ago. He was James Buchanan, arguably the nation's worst president.

In the interim, there have been a few competent congressional leaders from the state and some very influential local and state officials, stretching from Philadelphia Mayor Richardson Dilworth a half-century ago to Rendell today.

On the national level, Pennsylvania has been AWOL. Specter and former Democratic Gov. Milton Shapp each sought the presidential nomination; both candidacies were a joke. The unsuccessful 1880 Democratic presidential nominee, Winfield Scott Hancock, and the losing 1884 GOP nominee, James G. Blaine, were from Pennsylvania. But Hancock barely lived in the state after joining the military, and Blaine left it well before he ran for the White House.

The only semi-serious presidential effort Pennsylvania apologists cite was when the estimable Republican governor, William Scranton, tried to take the nomination from Barry Goldwater in 1964. Scranton was clobbered in a candidacy that barely lasted a month.

This is also one of the few large states that has never elected a woman or a black person governor or senator. Its politics are dominated by parochial people and matters.

"Pennsylvania politicians, unfortunately, have been more concerned about pork and patronage than national issues," said Madonna.

The latest Specter saga only reinforces that tradition.

Albert R. Hunt is Bloomberg News' executive editor for Washington. He can be contacted at ahunt1@bloomberg.net.