San Juan, Puerto Rico: Hillary Clinton sought to make the most of her last-stand victory on Sunday here in Puerto Rico, telling superdelegates who ultimately will pick the Democratic nominee: "The people have spoken and have chosen their candidate."

Making her best case in an increasingly desperate bid to stave off the nomination of Barack Obama, Clinton declared to a ballroom of cheering backers, "We are winning the popular vote. Of that there can be no doubt."

Later, to the travelling press corps on her campaign plane, Clinton reiterated her determination to stay in the race. "I think the evidence is accumulating that I'm the stronger candidate," she said. "I think my obituary is yet to be written."

Obama, who mostly ignored the primary here and holds an unshakeable lead in pledged delegates, congratulated Clinton from South Dakota with a none-too-subtle jab - saying she will be a "great asset" in Obama's fight against presumptive GOP nominee John McCain.

The primary here came a day after leaders of the party dealt Clinton a serious setback, seating the Florida and Michigan delegations at half-strength and closing off her last chance at a big delegate gain.

Her aides have threatened to fight that deal all the way to the convention - and Clinton told reporters that she was still deciding whether to challenge the Michigan decision.

Hectic season

She also said that the superdelegates might "change their minds" and that she would appeal to them once they had time for reflection after the hectic primary season ends.

Asked about her immediate plans, she said, "I'm sort of a day at a time person".

With Obama essentially conceding the primary on Saturday, Clinton handily won on Sunday with 68 per cent of the vote to Obama's 32 per cent with nearly all precincts reporting.

That left Obama just 49 delegates short of claiming the nomination, after he picked up 17 of the 55 at stake here.

Obama's campaign said he expects to be within about 30 delegates of the needed 2,118 after the last two primaries today in South Dakota and Montana, and Obama aides have grown bolder about predicting the nomination will be wrapped up this week.

'I will keep running'

Hillary Clinton has shrugged off calls to drop out of the US Democratic presidential race and said she will keep running "until there is a nominee".

But rival Barack Obama has opened a nearly insurmountable lead in their fight for the right to face Republican John McCain in November's presidential election, and is about 45 delegates short of clinching the nomination.

Here are some possible reasons why Clinton is staying in the race, at least through Tuesday when the last two contests are held in Montana and South Dakota:

  • She may want to continue so she feels like she has exhausted her options and explored every last possible avenue.
  • She could be hoping wins in the final contests will help bolster her claim an edge in the popular vote. While national popular vote plays no role in the selection process, a Clinton lead could sway superdelegates to her side.
  • She could be staying in the race to see if Obama makes a gaffe or becomes embroiled in another controversy that would rekindle voter concerns about his inexperience and make her appear the stronger candidate. She could then make the case to superdelegates that she has the best chance to beat McCain.
  • She could be trying to pressure Obama to add her to the ticket as his vice presidential nominee.
  • Clinton, whose campaign is more than $20 million in debt, may need more time to raise money and pay off her campaign debts, including the more than $11 million she has given the campaign from her own pocket.
  • She could be angling for a leadership role in the US Senate.

- Reuters