From CBS News' Maria Gavrilovic:
TROY, MICH. -- Just a day before the end of the Democratic primary season, Barack Obama's campaign is not yet confident that they will have the delegates needed to clinch the nomination by tomorrow evening. Despite hosting what is being touted as a "major" rally kicking off the next phase of the campaign, Obama is still courting superdelegates today. He spoke to superdelegates this morning and will continue to do so through tomorrow evening.
According to communications director Robert Gibbs, the campaign is confident that all superdelegates will make a decision within the next 48-72 hours. He said many supers chose to wait until the last primaries in order to decide who to support.
Once Obama clinches the nomination, Gibbs acknowledged they will have to campaign hard for Clinton voters. However, he dismissed the notion that the Democratic Party will be disenfranchised going forward, and drew an analogy to the Bush-McCain contest in 2000, saying that, eventually, bitter McCain supporters came around and supported Bush.
At a town hall meeting here today, Obama frequently spoke about a potential general election match up with McCain and vowed to work with Clinton this fall.
"Let me tell ya something, first of all, Senator Clinton has run an outstanding race, she is an outstanding public servant and she and I will be working together in November," Obama said.
"And I think all of us will be unified in making sure that George Bush's economic policies and George Bush's foreign policies are also not going to the White House."