U.S. Sen. Arlen Specter on Tuesday lost a Democratic primary in his bid for a sixth term after taking the risky step of switching from the GOP.
Voters picked U.S. Rep. Joe Sestak as the party's nominee and rejected the 80-year-old Specter in his first Democratic campaign since his Republican Party defection.
With 93 percent of precincts reporting, Sestak received 520,479 votes, or 54 percent; Specter received 446,281 votes, about 46 percent.
Sestak took the podium at a suburban Philadelphia military academy to speak to supporters amid shouts of "Joe! Joe!" Joe!"
"This is what Democracy looks like," he yelled. "A win for the people over the establishment, over the status quo, even over Washington, D.C."
The vote also was a defeat for President Barack Obama, who supported Specter when he abandoned the Republican Party last year. In speaking briefly to supporters at a downtown Philadelphia hotel after the race was called, Specter thanked Obama for his support.
Specter said he had called Sestak to congratulate him and tell him "I think it's vital to keep this seat in the Democratic Party and I will support him."
Specter left while holding hands with his wife, Joan. He didn't answer questions from reporters.
The moderate Specter had cast his switch as a decision of principle after inflaming the GOP by voting for Obama's economic stimulus bill. But many Democratic voters questioned his motives.
Sestak, 58, faces Republican Pat Toomey in the fall election.
Specter has been a fixture in American politics for three decades and served in the Senate since 1981, and his switch to the Democrats was a theme that dominated the race.
Obama and other top Democrats embraced Specter, who used his willingness to cross party lines on key votes to bolster his clout in Congress.
Sestak, a retired Navy vice admiral who has represented a suburban Philadelphia district since 2007, accused Specter of switching parties to save his job. He said Specter couldn't be trusted to support Democratic Party values.
In the days before the primary, Specter and Sestak also argued over who had the best chance of beating Toomey in the fall.
Specter leaned heavily on Obama's endorsement, repeatedly citing a television ad that used footage from a September rally in Philadelphia at which Obama spoke and get-out-the-vote efforts by the key unions backing him.
Sestak tried to harness voter anger over political gridlock and the recession, with Pennsylvania's unemployment rate at 9 percent, its highest in more than a quarter-century.
Sestak called Specter, who has overcome a brain tumor, cardiac arrest following bypass surgery and two bouts with Hodgkin's disease, "truly courageous." He said while they've disagreed, his opponent has achieved much good in his long career.
"He has devoted his entire life to public service, and he and his lovely wife, Joan, deserve our thanks for that," Sestak said.