Senator Arlen Specter concedes defeat in Pennsylvania to Representative Joe Sestak

Voters in Pennsylvania today decided to end the legislative career of longtime Senator Arlen Specter, who defected from the Republican Party last year and became a Democrat in the hopes of improving his chances of reelection.

Specter conceded the race to Representative Joe Sestak, his Democratic challenger, about an hour ago, at 10:20 PM Eastern (7:20 PM Pacific).

Up until three weeks ago, Specter's chances of holding on seemed decent. But once Sestak began to air television ads showing his opponent with George W. Bush and Sarah Palin, and implying that he was nothing but an opportunist, Specter's support began collapsing. Polls indicated that voters were turning to Sestak.

Sestak did a good job of getting Democratic voters to ask themselves why Specter was on their ballots, and then answer that question by concluding that Specter's primary motivation was self-preservation, not a desire to advance Democratic ideals and progressive policy directions.

Sestak must now fend off a challenge from likely Republican nominee Pat Toomey (who ran agaisnt Specter in the Republican primary four years ago). The Philadelphia Inquirer reports that Specter was gracious in defeat:

He said he 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."

In brief remarks at his Sheraton Philadelphia City Center election headquarters, he said: "It's been a great privilege to serve the people of Pennsylvania and it's been a great privilege to be in the United States Senate. I'll work very very hard for people of the Commonwealth in the coming months."

As of 8:30 PM Pacific Time, results were:

Democratic primary for U.S. Senate
Joe Sestak: 53.7% (501,117 votes)
Arlen Specter: 46.3% (432,710 votes)