By John Whitesides, Political Correspondent
WASHINGTON (Reuters) - Barack Obama and Hillary Clinton endtheir historic Democratic presidential battle on Tuesday withtwo nominating contests that could help Obama clinch thenomination and push Clinton from the race.
Democrats in South Dakota and Montana cast the final votesin a gruelling battle for the right to face Republican JohnMcCain in November's presidential election, with 31 delegatesto the August convention in Denver at stake.
Obama is within about 40 delegates of the 2,118 he needs tocapture the nomination and become the first black nominee of amajor U.S. political party.
He could hit that number as soon as Tuesday night dependingon how quickly he wins commitments from nearly 200 uncommittedsuperdelegates -- party officials who are free to back anycandidate.
"There are a lot of superdelegates who are waiting for thelast couple of contests but I think that they are going to bemaking decisions fairly quickly after that," Obama toldreporters in Michigan on Monday.
Voting ends in South Dakota at 7 p.m. MDT/9 p.m. EDT (2a.m. British time), and in Montana an hour later, with resultsexpected shortly after.
Clinton and her campaign sent mixed signals on Monday abouthow long she would stay in a presidential race that she beganas a heavy favourite but now has little chance of winning.
Campaigning in South Dakota, Clinton said the end of thevoting on Tuesday marked "the beginning of a new phase of thecampaign" in which she will plead her case to superdelegatesthat she would be the strongest candidate against McCain inNovember.
"The decision will fall to the delegates empowered to voteat the Democratic convention. I will be spending the comingdays making my case to those delegates," she told supporters inYankton, South Dakota.
But her husband, former President Bill Clinton, soundedlike he was counting down the hours at a campaign stop in SouthDakota on Monday. "This may be the last day I'm ever involvedin a campaign of this kind," he said.
One of Clinton's top supporters, Gov. Ed Rendell ofPennsylvania, told CNN he expected her to spend Wednesday andThursday making her pitch to superdelegates.
'OBAMA TO GET DELEGATES HE NEEDS'
"I don't think it's going to prevail, to be candid," hesaid. "Senator Obama is going to get the delegates he needscertainly by the end of the week, then I think Senator Clintonis going to do the right thing and move fairly decisively tounify the party and we will all follow her lead."
With no more campaign trips to plan, workers who handleClinton's advance travel arrangements have been told to go toNew York or head home until further notice, aides said.
Obama plans a victory celebration to kick-off thegeneral-election campaign against McCain after the South Dakotaand Montana polls close on Tuesday night. He will hold it atthe Xcel Energy Centre in St. Paul, Minnesota -- the site ofthe Republican convention in September.
The Obama campaign has been urging superdelegates to maketheir endorsement before the voting ends on Tuesday, so thedelegates he wins in the two states can put him over the top inthe Democratic race.
A group of 17 uncommitted Senate Democrats met on Monday todiscuss a potential endorsement of Obama. Many are poised toannounce either on Tuesday or wait another day to give Clintona chance to bow out, Senate aides said.
Rep. James Clyburn of South Carolina, the third-rankingDemocrat in the U.S. House of Representatives and thetop-ranking black member of Congress, was one of sevensuperdelegates who said they would back Obama on Monday.
He plans a formal endorsement on Tuesday, and other Housemembers are expected to follow his lead, party sources said.
Both Obama and Clinton will speak to a pro-Israeli lobbyinggroup in Washington on Wednesday, and Obama told reporters heexpected to be talking to Clinton again soon.
He said he told her in a phone conversation on Sunday that"once the dust settled I was looking forward to meeting withher at a time and place of her choosing."
(Additional reporting by Caren Bohan, Thomas Ferraro andEllen Wulfhorst; editing by Mohammad Zargham)
(To read more about the U.S. political campaign, visitReuters "Tales from the Trail: 2008" online athttp://blogs.reuters.com/trail08/)
