Sen. Arlen Specter (D-Pa.) earned an endorsement from the Pennsylvania chapter of AFL-CIO in his bid for a sixth term.

Specter tweeted Tuesday from his verified account @SenArlenSpecter:

"Thank you, thank you, thank you, PA AFL-CIO. I'm proud to have your endorsement and support."

The former Republican has already received the endorsement of the Pennsylvania Democratic Party.

Specter is facing a primary challenge from Rep. Joe Sestak, but poll numbers show the incumbent leading by a wide margin. Sestak has failed to attract name recognition across the state throughout the primary race.

Former Rep. Pat Toomey (R), the likely Republican nominee, is running neck-and-neck with Specter.

Cross-posted to the Ballot Box