In Historic Vote, Obama Officially Claims Democratic Nomination

DENVER -- Sen. Barack Obama (Ill.) was formally nominated as the Democratic Party's presidential candidate today, making him the first African American to be placed one step from the White House.

And in an extraordinary piece of theater, Obama made a surprise appearance before the convention tonight immediately following vice presidential nominee Joseph Biden's acceptance speech. An energized Obama bounded onto the stage, kissed Biden's wife, Jill, on the lips and then hugged Biden.

"I want everybody to understand why I'm so proud to have Joe Biden" on his ticket "to take America back," Obama said to thunderous applause.

The historic moment came after Sen. Hillary Rodham Clinton (N.Y.), who narrowly lost to the Illinois senator, asked the cheering delegates to unanimously throw their support to Obama.

Several hours later, former President Bill Clinton vigorously embraced Obama's candidacy, making the case that the party's nominee is ready to be commander-in-chief and ratifying his choice of Biden as his running mate, even if it was not Clinton's wife.

"Barack Obama is ready to lead America and restore American leadership in the world," the former two-term president said. "Barack Obama is ready to be President of the United States."