Pennsylvania is losing a congressional seat due to the new census, but more worrisome is the loss of Sen. Arlen Specter from Washington's halls of power.

The state's longest-serving senator in history will leave office on Jan. 3, after losing last spring's Democratic primary. He has represented Pennsylvania with determination, independence, and skill for 30 years.

During his long tenure, Specter, 80, has done his best to represent all Pennsylvanians. It was no easy feat in a state that, in the past decade, elected conservative Republicans Pat Toomey and Rick Santorum, while also twice electing liberal Democratic Gov. Rendell.

Trying to balance those competing ideological forces ended up costing Specter his legislative career. He was a Republican for 44 years, then switched parties in 2009 after it became clear he couldn't beat Toomey in an increasingly conservative Republican Party primary.

But neither could he win the Democratic primary against Rep. Joe Sestak, who ran to his left. The swing senator from the swing state didn't get to retire from Congress on his own terms.

The former Philadelphia district attorney's career in Congress was marked by tenacity and clout. A cancer survivor, Specter succeeded in tripling the National Institutes of Health budget for research to cure the disease.

As a longtime appropriator, he directed hundreds of millions of dollars to Pennsylvania's schools and hospitals, and for its highways and crime-prevention programs. Specter's support of the Aker Philadelphia Shipyard is just one example of his success in bringing home federal dollars.

He demanded high standards of the judiciary. His opposition to Supreme Court nominee Robert Bork in 1987 was one of his finest moments, but Specter paid a price for resisting party-line votes.

By the time Republican George W. Bush became president, conservatives endorsed Specter for chairman of the Judiciary Committee only after he promised to move Bush's nominees quickly through the panel.

Five presidents of both parties relied on Specter's counsel on matters ranging from the Middle East to federal wiretapping laws. He was respected for his hard work and insight.

The steady polarization of both parties in Congress eroded the middle ground where Specter made his living. Conservatives derided him as a RINO - Republican In Name Only. A Democratic leader complained that Specter voted with the left side of the aisle only when they didn't need his vote.

But Democrats needed Specter's vote, and got it, early in President Obama's term. Specter was one of only three GOP lawmakers to vote for Obama's $787 billion economic-recovery package in February 2009, after insisting that tax cuts be a part of the deal. That courageous vote ended up driving Specter out of the GOP.

Ironically, Senate Republican leaders this month agreed with Obama on an even larger economic-stimulus plan - a two-year, $900 billion deal to extend Bush-era tax cuts, provide other tax breaks, and pay for more unemployment benefits. It wasn't so different from the plan that clinched Specter's outcast status with the GOP.

For much of his Senate career, Specter's seniority benefitted Pennsylvanians. In the upcoming 112th Congress, the state will have no one to match that clout.