US:MONTANA AND South Dakota vote today in the last primaries of the Democratic presidential contest amid growing expectations that Barack Obama will secure the party's nomination within hours of the polls closing.
Despite a resounding victory for Hillary Clinton in Puerto Rico on Sunday, some of the New York senator's closest allies said they expect her to quit the race within days, and her husband acknowledged that yesterday may have been his last day of campaigning.
"This may be the last day I'm ever involved in a campaign of this kind," former president Bill Clinton said in Millbank, South Dakota.
"I thought I was out of politics, until Hillary decided to run. But it has been one of the greatest honours of my life to go around and campaign for her for president."
Former Iowa governor Tom Vilsack, a national co-chairman of Mrs Clinton's campaign, said the outcome of the nominating race was now beyond doubt.
"It does appear to be pretty clear that Senator Obama is going to be the nominee. After Tuesday's contests, she needs to acknowledge that he's going to be the nominee and quickly get behind him," he said.
Mrs Clinton claims to have won more popular votes than Mr Obama and, in her victory speech in Puerto Rico, she repeated her assertion that she is the stronger candidate to face Republican John McCain in November.
Her campaign is already showing signs of winding down, however, with employees urged to submit all unclaimed expenses receipts by the end of this week and advance staff informed that they will no longer be needed.
With the nomination within his reach, Mr Obama yesterday praised Mrs Clinton's campaign and sought to quell fears that the party will be unable to unite after the primary battle is over.
"There's been thinking, well, are the Clinton folks going to support the Obama folks and are the Obama folks going to get together with the Clinton folks," Mr Obama told an audience in Try, Michigan.
"Senator Clinton has run an outstanding race, she is an outstanding public servant and she and I will be working together in November."
Mr Obama will hold his election party tonight in St Paul, Minnesota, at the same venue the Republicans have chosen for their convention next September, while Mrs Clinton is returning to New York for her event.
Mr McCain returned yesterday to his attack on Mr Obama's foreign policy, criticising the Democrat for voting against the designation of Iran's Revolutionary Guard as a terrorist organisation.
"He opposed this resolution because its support for countering Iranian influence in Iraq was, he said, a 'wrong message not only to the world, but also to the region'. But here, too, he is mistaken. Holding Iran's influence in check, and holding a terrorist organisation accountable, sends exactly the right message - to Iran, to the region and to the world," Mr McCain told the American Israel Political Action Committee.