The Big Story: Obama clinches Democratic nomination From The Associated Press

ST. PAUL, Minn.—Before a crowd of cheering thousands, Sen. Barack Obama of Illinois laid claim to the Democratic presidential nomination Tuesday night, taking a historic step toward his once-improbable goal of becoming the nation's first black president.

Hillary Rodham Clinton maneuvered for the vice presidential spot on his fall ticket without conceding her own defeat.

"America, this is our moment," the 46-year-old senator and one-time community organizer said in his first appearance as the Democratic nominee-in-waiting. "This is our time. Our turn to turn the page on the policies of the past."

On the final night of the primary season, Clinton won South Dakota and Obama, Montana.

The former first lady praised her rival, whom she said "has inspired so many Americans to care about politics and empowered so many more to get involved. And our party and our democracy is stronger and more vibrant as a result."

"I am committed to uniting our party so we move forward stronger and more ready than ever to take back the White House in November," she said in a final-night rally in New York.

But she neither acknowledged Obama's victory nor offered a concession of any sort.

Instead, she 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."

On a conference call with other New York lawmakers, Clinton, a New York senator, said she was willing to become Obama’s vice presidential nominee if it would help Democrats win the White House, according to several participants in the call.

Only 31 delegates were at stake in the two states on the night's ballot, the final few among the thousands that once drew Obama, Clinton and six other Democratic candidates into the campaign to replace Bush and become the nation's 44th president.

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 2,144 by the AP count.

Other names have been floated as possible running mates for Obama, including New Mexico Gov. Bill Richardson, former North Carolina Sen. John Edwards, and governors including Janet Napolitano of Arizona, Kathleen Sebelius of Kansas and Tim Kaine of Virginia. Also mentioned are foreign policy experts including former Georgia Sen. Sam Nunn, Connecticut Sen. Chris Dodd and Delaware Sen. Joe Biden, and other senators such as Missouri’s Claire McCaskill and Virginia’s Jim Webb.

Obama could also look outside the party to people such as anti-war Republican Sen. Chuck Hagel of Nebraska or independent New York Mayor Mike Bloomberg. Or he could look to one of his prominent supporters such as former Sen. Tom Daschle of South Dakota or try to bring on a Clinton supporter, such as Indiana’s Sen. Evan Bayh or retired Gen. Wesley Clark.