obama camp making a run for pennsylvania.
cnn: Obama accepted the endorsement, saying, "Bob is such gracious person. I did not press him on this endorsement. There are others I press."
He said Casey's backing "meant more to me as any endorsement I've received on the trail because I knew it was coming from the heart." Watch as Casey backs Obama »
Casey is a first-term senator and son of a popular former Gov. Bob Casey Sr. A Catholic, the lawmaker could help Obama make inroads in Pennsylvania among Catholic voters, a bloc that has favored Clinton in most other contests.
"I know that it wasn't based on political calculation, and that's the kind of person I want standing alongside me, that's the kind of leadership that Bob will bring alongside me when I am president of the United States of America," Obama said, later hugging the senator.
Obama also lashed out at the presumptive Republican nominee's policy on Iraq, saying Sen. John McCain "wants to continue George Bush's economic policies. He wants to keep troops in Iraq potentially for 100 years."