Barack Obama sealed the Democratic presidential nomination June 3, a historic step toward his once-improbable goal of becoming the first black U.S. president. A defeated Hillary Rodham Clinton maneuvered for the vice presidential spot on his ticket.

Barak Obama AP PHOTO

Obama's victory sets up a five-month campaign against Republican John McCain, a race between a 46-year-old opponent of the Iraq War and a 71-year-old former Vietnam prisoner of war and staunch supporter of the current U.S. military mission.

They will vie to succeed President George W. Bush, whose popularity has plummeted as the economy weakens, gasoline and food prices soar and the war continues in its sixth year.

Obama, a first-term Illinois senator who was virtually unknown across America four years ago, defeated Clinton in a 17-month marathon for the Democratic nomination.

His victory had been widely assumed for weeks. But Clinton's declaration of interest in becoming his running mate was unexpected.

The New York senator expressed it in a conference call with the congressional delegation from her state after congresswoman Nydia Velazquez predicted Obama would have great difficulty winning the support of Hispanics and other voting blocs unless Clinton was on the ticket.

"I am open to it" if it would help the party's prospects in November, Clinton replied.

Clinton's comments raised anew the prospect of what many Democrats have called a "Dream Ticket" that would put a black man and a woman on the same ballot.