WASHINGTON — Sen. Barack Obama pushed close to victory in the marathon Democratic presidential race Monday on the eve of a final pair of primaries amid signs that Sen. Hillary Rodham Clinton was preparing to acknowledge defeat.

Said a confident-sounding Obama: “I told her that once the dust settled I’m looking forward to meeting with her at a time and place of her choosing.” He said he spoke with Clinton on Sunday when he called to congratulate her on winning the Puerto Rico primary. He did not describe her response.

He also said he would begin thinking about a vice presidential running mate “the day after I have gotten that last delegate needed to officially claim the nomination.”

Clinton’s advisers privately predicted she would lose both primaries today, in Montana and South Dakota. Thirty-one delegates are at stake in the two contests.

Clinton planned to meet with advisers at her home in Chappaqua, N.Y., today.

The former first lady gave no public hint of quitting the race. But her husband, former President Clinton, strongly suggested otherwise. “This may be the last day I’m ever involved in a campaign of this kind,” he said as he stumped for his wife in South Dakota.

Clinton advisers said her options included dropping out tonight and endorsing Obama to making a final effort to convince uncommitted superdelegates — members of Congress and other party leaders — that she would be a stronger rival to apparent Republican nominee Sen. John McCain.

However, Clinton aides stressed she had no plans to withdraw from the race tonight.

Another possibility, according to senior Clinton advisers, is what they dubbed the “middle option,” for Clinton to suspend her campaign, acknowledging that Obama has crossed the delegate threshold but keeping her options open until the convention in late August.

Obama was 41.5 delegates shy of the 2,118 needed to clinch the nomination at the party’s convention in Denver, according an Associated Press count Monday. Clinton had 1,917.5.

Rep. Jason Altmire of Pennsylvania, who is uncommitted, said Obama’s goal was to be in position to seal the nomination tonight, once the votes are tallied and delegates awarded from primaries in Montana and South Dakota.

Obama stopped short of a flat prediction that he would be able to claim victory tonight when the delegates were allocated after the day’s primaries. But he said, “It is my sense that between Tuesday and Wednesday we have a good chance of getting that number of delegates” needed for victory.

Democratic Party officials said that if Obama failed to gain 2,118 delegates by tonight, one possibility under discussion was for Senate Majority Leader Harry Reid, House Speaker Nancy Pelosi and West Virginia Gov. Joe Manchin, who is head of the Democratic Governors’ Association, to issue a statement Wednesday urging superdelegates to state their preferences as soon as possible.

In a conference call with donors, Harold Ickes, a top Clinton aide, conceded Monday that Obama was likely to reach the delegate threshold by Wednesday, according to one participant who described the conversation on condition of anonymity.

Delegate watch

Sen. Hillary Rodham Clinton: 1,917.5

Sen. Barack Obama: 2,076.5

Needed to nominate: 2,118

Total delegate votes: 4,234

Washington state superdelegates

Washington state’s 17 Democratic superdelegates and their endorsements:

Sen. Hillary Rodham Clinton: U.S. Sens. Patty Murray and Maria Cantwell, U.S. Reps. Norm Dicks and Jay Inslee, King County Executive Ron Sims and Democratic Party Vice-chairwoman Eileen Macoll

Sen. Barack Obama: Gov. Chris Gregoire; U.S. Reps. Adam Smith, Brian Baird, Rick Larsen and Jim McDermott; State Democratic Party Chairman Dwight Pelz; Democratic National Committee Member Pat Notter; and Democratic National Committee member David McDonald

Undeclared: Democratic National Committee member Ed Cote, Democratic National Committee member Sharon Mast and former U.S. House Speaker Tom Foley

Remaining primaries

Today: Montana and South Dakota (31 delegates combined). Signs point to an Obama win in both states.

Associated Press