ABC News' Eloise Harper reports: Sen. Hillary Clinton, D-N.Y., told her delegates this afternoon that they had been "released." Loud boos were heard in the room when she said to the thousands of Clinton delegates that, "as part of that tradition, I am here today to release you as my delegates."
While there is no formal process of releasing delegates, since they are not bound and free to vote for whoever they want, her public urging is seen as another gesture towards forging unity. It was also an opportunity to express her gratitude to supporters. Clinton thanked everyone in the room many times, and oftentimes, the boisterous crowd shouted back 'thank you!'
"I want you to know that this has been a joy," Clinton said. "Yes, we didn't make it. But boy, did we have a good time."
A roll call vote is slated to take place around 5 p.m. ET, but it will likely be aborted. According to Obama campaign advisors, an agreement has been made that the roll call will halt at some point and the convention will move to nominate Sen. Barack Obama, D-Ill., by acclamation.
Clinton told the delegates that she signed her ballot for Obama this morning, but said she understood that others would 'vote with their hearts.'
"I have spoken to many of you who have expressed your questions about what you should do. Now, many of you feel a responsibility to represent the voters in your state. And others of you, after this long journey, want the chance to vote for what’s in your heart. Now, still others will be voting for Sen. Obama because they want to demonstrate their personal commitment for the unity of this party behind our nominee. I am not telling you what to do. You come here from so many different places, having made this journey and feeling in your heart what is right for you."
The crowd cheered loudly when Clinton mentioned that there would be a roll call vote.
"It is traditional that we have nominations, that we have a roll call, that we have candidates who look for ways to work to make sure that we come out of here ready to win in November," Clinton said. "At the end of today, we will nominate Barack Obama and Joe Biden for the president and vice president of the United States."
After thanking the crowd and shaking hands, Clinton heads to the Pepsi Center for the roll call vote.
ABC News' David Chalian contributed to this report.