BARACK OBAMA IS THE DEMOCRATIC PRESIDENTIAL NOMINEE: But Hillary Clinton refuses to concede.

*It's official. Illinois Senator Barack Hussein Obama can now say he is the Democratic Party's nominee to run against the Republican Party's nominee John McCain in November.

Obama's claim to the nomination is also historic because it marks the first time that a black person has ever headed the ticket of a major American political party.

"America, this is our moment," the 46-year-old senator said in his first appearance as the Democratic nominee-in-waiting. "This is our time; our time to turn the page on the policies of the past." (Read the full text of Obama's nomination victory speech here.)

Meanwhile, his Democratic opponent, New York Senator Hillary Rodham Clinton praised him in an appearance before her supporters, although she neither acknowledged his victory in their grueling march through the primaries nor did she offer any concessions.

Instead, she said she was committed to a unified party, and said she would spend the next few days determining "how to move forward with the best interests of our country and our party guiding my way."

But at what price? Or more succinctly, what does she want? That's what a lot of watchers are asking. Of course the general thinking is that the former First Lady is angling for a spot on the ticket as Obama's vice presidential running mate.

Meanwhile, Obama's victory set up a five-month campaign with Republican Sen. John McCain of Arizona, a race between a first-term Senate opponent of the Iraq War and a 71-year-old Vietnam prisoner of war and staunch supporter of the current U.S. military mission.

McCain spoke first, in New Orleans, and he accused his younger rival of voting "to deny funds to the soldiers who have done a brilliant and brave job" in Iraq." Americans, he added, should be concerned about the judgment of a presidential candidate who has not traveled to Iraq yet "says he's ready to talk, in person and without conditions, with tyrants from Havana to Pyongyang."

McCain agreed with Obama that the presidential race would focus on change.

"But the choice is between the right change and the wrong change, between going forward and going backward," he said.

Obama responded quickly, pausing in his own speech long enough to praise Clinton for "her strength, her courage and her commitment to the causes that brought us here tonight."

As for his general election rival, he said, "It's not change when John McCain decided to stand with George Bush 95 percent of the time, as he did in the Senate last year. It's not change when he offers four more years of Bush economic policies that have failed to create well-paying jobs. ... And it's not change when he promises to continue a policy in Iraq that asks everything of our brave young men and women in uniform and nothing of Iraqi politicians."

Obama sealed his nomination, according to The Associated Press tally, based on primary elections, state Democratic caucuses and support from party "superdelegates." It takes 2,118 delegates to clinch the nomination at the convention in Denver this summer, and Obama had 2,154 by the AP count.

The now presumptive Democratic Presidential Nominee, Barack Obama: