Barack Obama is just a few dozen delegates away from the Democratic Party's nomination.
He could reach it tonight if he has enough support from super delegates.
Top Clinton campaign officials reportedly say she will acknowledge Obama's nomination if he reaches that magic number, but her campaign manager is casting doubt on whether she'll do that tonight.
As voters headed to the polls in South Dakota and Montana, Clinton left open the possibility that she could press her fight against Barack Obama right up to the convention, but with Obama just a few dozen delegates away from claiming the nomination
Clinton's campaign chief said she won't stand in the way.
"If he happens to get the numbers, then Hillary will congratulate him as the nominee and I think Hillary will continue for the rest of campaign season to go out there and fight on the issues that matter to her: health care, education," said Terry McAuliffe.
As Clinton headed back to New York campaign workers were ordered to get all their paperwork in order and go home.
For Obama to claim the nomination tonight he needs holdout super delegates to commit now.
Congressman James Clyburn, the highest-ranking African American in Congress, sided with Obama this morning.
"He elevated the political debate in this country, he energized voters like I have not seen energized voters since the 1960s," Clyburn said.
Still, several other lawmakers want to wait until the last votes are cast.
"A lot of us feel that the sooner this thing comes to a close, that we have a nominee, the better off everyone is going to be in our party," said Iowa Senator Tom Harkin.
For Obama, it will be a night for celebration, whether he reaches the magic delegate number or not, and for Hillary Clinton time to decide when, or whether, to leave the stage.
Clinton and Obama both plan to be here in Washington tomorrow, perfect timing for a joint appearance should they choose to make one.