Hillary Clinton is waiting to take her final bow on the stage of the Democratic nomination contest, even though the lights are dimming and the attention of the audience is turning elsewhere.

Barack Obama, the presumptive winner of the 15-month saga, is increasingly impatient for the curtain to fall. Tomorrow he will hold a rally in St Paul, Minnesota — where the Republicans hold their nominating convention this autumn — to demonstrate how he is already taking the fight to John McCain.

Yesterday he spoke warmly of Mrs Clinton: "She is going to be a great asset when we go into November to make sure we beat the Republicans." But he is also slowly ratcheting up the pressure on her to step aside, telling a brief press conference: "I think that Senator Clinton and former President Clinton love this country. They love the Democratic Party ... And so I trust that they’re going to do the right thing.”

Aides suggest that he may declare victory even without a formal concession from Mrs Clinton. “He’s not going to wait by the phone like a high-school girl waiting for a date,” said one. “That’s not Barack Obama.”

His spokesman, Robert Gibbs, said yesterday: “I think sometime this week we’ll probably have a nominee for the Democratic Party and we can get talking about the need to bring change to this country.”

Mrs Clinton won last night’s Democratic primary in Puerto Rico by a margin of more than two to one. Since March 4 she has won most of the primary contests, including three of the last four by landslides. But, with delegates awarded proportionately, Mr Obama is still on course to cross the finishing line after tomorrow’s final primaries in Montana and South Dakota. He is said to have dozens of super-delegates lined up to help push him over the finishing line this week.

After her largely symbolic victory in Puerto Rico, Mrs Clinton made an explicit appeal to the fewer than 200 remaining uncommitted super-delegates, claiming that she would have more votes than Mr Obama and that she had won in the big swing states the Democrats need in November.

"In the final assessment I ask you to consider these questions. Which candidate best represents the will of the people who voted in this historic election? Which candidate is best able to lead us to victory in November and which candidate is best able to lead our nation as our president in the face of unprecedented challenges at home and abroad?" she asked.

Mr Obama's aides questioned her claims to be winning the popular vote, pointing out that this tallies for caucuses in Iowa, Nevada, Maine and Washington state — where no official candidate’s popular vote is available.

On Saturday Clinton supporters made voluble protests against a party rules committee decision to give delegates from disputed primaries in Florida and Michigan half a vote each at the Democratic convention in Denver. This gave her a net gain of 26.5 votes, barely enough to make a dent in Mr Obama’s forbidding delegate lead.

Yesterday, unnamed sources close to Mrs Clinton were quoted as saying that she knows the race is lost, suggesting her home state of New York could be the venue for a concession speech this week. Today, there are reports that the Clinton campaign is already shedding staff.

There are mixed messages coming out of her campaign. Harold Ickes — who mounted a characteristically vigorous effort on Mrs Clinton’s behalf at the rules committee meeting on Saturday — announced that she was reserving the right to appeal against a decision that gave Mr Obama four of her delegates from Michigan.

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