Barack Obama Makes Surprise Appearance After Joe Biden DNC Speech

Bill Clinton: 'Yes We Can, But First You Need to Vote for Him'

While all the party unity stagecraft was carefully planned, it was a speech tonight by former President Bill Clinton that threatened to remind voters of just how divided the party was during the bitter and lengthy primary campaign.

When the former president walked on stage Wednesday night, the crowd erupted into such wild applause that he asked them to stop.

"I love this, but we have important work to do tonight," he said after basking in the glow of the applause.

"First of all," he said, "I am honored to be here tonight to support Barack Obama."

Clinton added, "And to warm up the crowd for Joe Biden -- though as you'll soon see, he doesn't need any help from me. I love Joe Biden, and America will too."

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Praising his wife, Clinton said the party's primary began with an "all-star line up and came down to two remarkable Americans locked in a hard-fought contest to the very end."

"In the end, my candidate didn't win," he said. "But I'm very proud of the campaign she ran: She never quit on the people she stood up for, on the changes she pushed for, on the future she wants for all our children. And I'm grateful for the chance Chelsea and I had to tell Americans about the person we know and love."

"Hillary told us in no uncertain terms that she'll do everything she can to elect Barack Obama," the former president said. "That makes two of us. Actually that makes 18 million of us -- because, like Hillary, I want all of you who supported her to vote for Barack Obama in November."

At one point in his speech, as the crowd cheered Obama's campaign refrain, "Yes we can! Yes we can!" Clinton ad-libbed, "Yes he can, but first you need to vote for him."

As of late afternoon, the two-term president had not finished his speech, and senior Obama campaign officials told ABC News that neither Obama nor anyone from the campaign had seen it.

That's rare. Even Hillary Clinton, Obama's closest primary rival, ran her speech by the Obama campaign before delivering it.

Perceived Tensions Between Obama, Bill Clinton

While Obama campaign officials said they weren't nervous about Bill Clinton's speech Wednesday, there may have been good reason to be nervous after a bitter primary battle in which the former president aggressively went after Obama in support of his wife's candidacy.

There are are perceived tensions between the man who will become the nation's first major party African-American presidential candidate, and the man who was once dubbed America's "first black president."

However, Bill Clinton said all the right words. Watching from the stands and rising to applaud him was potential first lady Michelle Obama, who sat beside Theresa Heinz Kerry, wife of 2004 Democratic presidential candidate John Kerry.

"Barack Obama is ready to lead America and restore American leadership in the world," Clinton told the cheering crowd. "Barack Obama is ready to honor the oath to preserve, protect and defend the Constitution of the United States. Barack Obama is ready to be president of the United States."

The former president was given a less desirable speaking slot Wednesday, addressing the crowd ahead of Kerry and New Mexico Gov. Bill Richardson, and not during the prime time hours that the major networks will carry the events. Richardson was eventually bumped from the Wednesday night program because they ran out of time, but will now speak Thursday night.