Obama: "Believe In What's Possible Again"

Barack Obama, who jetted PA for IN tonight, congratulated Hillary Clinton for winning a hard-fought and often nasty Keystone State primary contest.

"She ran a terrific race," Obama said plainly, despite a seven-week struggle that involved revelations about the Rev. Jeremiah Wright and Clinton's Bosnia landing and "bittergate."

Obama directed a significant segment of his most fighting words at John McCain, saying the GOPer backs President Bush's corporate tax cuts and Iraq policy.

"What he's not offering," Obama said of McCain, "is any meaningful change from the policies of George W. Bush."

Obama said that this election year the Democrats should not "calculate and poll test our positions." He said the party should "seek to regain not just an office but the trust of the American people." His Dem rival has not yet succeeded, as PA exit polls reinforced tonight, in convincing voters that she is trustworthy.

As he did after losses in NH, TX and OH, Obama reminded of his broader mission and message, that his campaign is about uniting Americans of all backgrounds, races and religions. The country's divisive politics, he said, should and can be overcome.

"While I will always listen to you, and be honest with you and fight for you every single day for the next four or eight years, if I have the opportunity to be president, I will also ask you to be a part of the change that we need," Obama said.

(JENNIFER SKALKA)