Hillary Clinton Could Bring Democrat Nomination to a Vote

Sources close to both Obama and Clinton told ABC News that the New York senator is highly unlikely to allow her name to be formally submitted for a roll-call vote on the convention floor. The Obama campaign wants to avoid such a vote, since it would underscore the party's splits and remind voters of the divisive primary campaign between the two Democrats.

The refusal to publicly announce her intentions is widely seen as a bargaining chip Clinton is holding on to as party officials negotiate logistics regarding her convention speech and other activities, according to several Democrats who are closely involved in the matter.

Clinton plans to hold a Web chat with supporters Thursday afternoon where she might clarify her convention role. In announcing the Web chat, she urged her supporters to continue to stay tuned to her Web site for updates about her convention activities.

But the very fact that details of her convention role remain unresolved less than three weeks before the Democrats descend upon Denver is a fresh sign of the difficulties the party will face at a convention when nearly half the delegates were chosen because of their support for a candidate who will not be the nominee.

"We will have this in hand for Sen. Clinton, should this be needed," said Castner, who said that she's already gathered about half the necessary signatures.

Castner said she and many other Clinton supporters will only feel as if their voices are being heard if they are allowed to vote for Clinton on a first ballot.

"It's been a tradition since the late 1800s -- it's a nominating convention, you vote, you nominate someone, and you come out unified. I don't see how alienating 1,800 delegates gives you party unity when we walk out of the stadium," she said. "Hillary delegates feel like we're not welcome, needed, or valued."

"I cannot believe that Sen. Clinton, after putting in that much time, energy and effort, would just say, ' Nah, take my name out,' " Castner said.