HARRISBURG, Pa. (AP) âÄî A national Republican group unleashed a statewide telephone blitz Wednesday against newly Democratic Sen. Arlen Specter âÄî reminding thousands of Pennsylvania Democrats that President George W. Bush endorsed him in 2004 and that Specter angered labor unions just weeks ago by opposing a bill to make it easier for workers to form unions. Spokeswoman Amber Wilkerson said the National Republican Senatorial Committee aims to reach 100,000 Democratic voters through Thursday. Specter, 79, stunned political observers Tuesday when he announced he was ending a four-decade relationship with the GOP and became a Democrat. One of only a handful of moderate Republicans in the Senate, Specter bluntly acknowledged that he was unlikely to win the nomination for a sixth term from a party that has grown increasingly conservative. The taped message from a man who introduces himself as “Jack” includes audio clips of Bush endorsing Specter in his last election campaign and of Specter criticizing the “card check” legislation that organized labor supports. In endorsing Specter for a fifth term in 2004, Bush called him “the right man for the United States Senate.” “I can count on this man âÄî see, that’s important. He’s a firm ally when it matters most,” Bush said. In the other clip, Specter says he would not supply the crucial 60th vote that Democrats need to overcome an expected GOP filibuster of the “card check” legislation when it is taken up later this year. “I think it is a bad bill and I’m opposed to it and would not vote to invoke cloture,” he said. Specter’s state campaign spokesman, Christopher Nicholas, responded by paraphrasing Winston Churchill. “Let them do their worst. We will do our best,” Nicholas said. ___ “Meet Arlen” audio clip of robocall message: http://tinyurl.com/c78633