The deliberations opened the possibility of the once-unwieldy presidential field narrowing to two septuagenarian men who represent opposite poles of the Democratic Party — and raised the question of whose side, if anyone’s, Warren will be on if it does.

“This decision is in her hands,” wrote campaign manager, Roger Lau, in an e-mail to Warren’s staff, “and it’s important that she has the time and space to consider what comes next.”

Senator Elizabeth Warren hunkered down in her Cambridge home on Wednesday to face the wrenching decision of whether to continue her beleaguered presidential campaign, speaking with a tight circle of advisers as her aides, social media accounts, and fund-raising apparatus fell mostly silent.


Whatever decision she makes could have an outsize influence on the race, since her supporters will help decide the fierce nomination fight now shaping up between Vermont Senator Bernie Sanders and former vice president Joe Biden. Sanders said he spoke to Warren on Wednesday by phone, telling reporters he wanted to respect her desire for time to make the decision on her own. A Biden spokesman would not comment on whether he spoke to Warren as well.

Some liberals urged Warren to drop out of the race and endorse Sanders in a last-minute effort to unify the left. Moderates including former South Bend, Ind., mayor Pete Buttigieg and billionaire Mike Bloomberg backed Biden after ending their campaigns this week.

But it was not clear whether Warren would rally behind Sanders or Biden, or simply withhold an endorsement should she choose to exit the race, making her a potential wild card in a race that could still hold some surprises.

“I don’t think it’s a given at all that she endorses Bernie Sanders or anyone,” said one Democratic operative familiar with her campaign who spoke on condition of not being identified.


Representative Ilhan Omar of Minnesota, a supporter of Sanders, took to Twitter Tuesday night to suggest Warren should get out of the race, but the leaders of groups backing Sanders were careful to avoid appearing too eager to push out Warren, the last woman standing in the top tier of the race.

“We’re not going to tell Elizabeth Warren…to get out of this race,” said Charles Chamberlain, the executive director of Democracy for America, who said he was not confident Warren would endorse Sanders if she drops out, or that her exit would necessarily be a boon to Sanders.

Some elements of Warren’s campaign were still chugging along on Wednesday. Her staffers in Michigan, which votes next week, made calls about a weekend of get-out-the-vote events. The venues in Arizona, Michigan, and Idaho where she is scheduled to hold campaign events in the coming days said she had not canceled.

But Warren faces a stark and unpleasant reality: A candidate who once rode a tide of excitement about her policy-focused presidential campaign to the top of the polls had finished third or worse in all 14 states that voted on Tuesday — including her home of Massachusetts.

Just days ago, her campaign had suggested it could amass enough delegates to play kingmaker at a brokered convention. But that plan now seems less plausible, since only Biden and Sanders consistently racked up delegates on Tuesday, and may find themselves in a position to amass enough to clinch the nomination on their own. By Wednesday afternoon, estimates showed Biden and Sanders each had more than 500 delegates in the ongoing count, while Warren had notched only about 60. A candidate needs 1,991 to win the nomination on the first ballot.


But there was a glimmer of hope for Warren. The race has been remarkably fluid and unpredictable, as evidenced by the way Biden benefited from an enormous surge of support on Tuesday, winning states he had barely campaigned in, following his win in South Carolina on Saturday.

“We also all know the race has been extremely volatile in recent weeks and days with front-runners changing at a pretty rapid pace,” Lau wrote in his e-mail to the staff, referencing a fact that may provide incentive for Warren to stay in the race and see if she can catch a last-minute surge of support.

Some of her supporters urged her to stay in the race at least until the next debate, on March 15, when she would likely be the only woman standing next to Biden and Sanders, each of whom have their own flaws and foibles. Hawaii Representative Tulsi Gabbard remains in the race, but has not met debate thresholds for months.

Howard Dean, the former Vermont governor who made his own decision to drop out of a presidential race in 2004 after initially resisting calls to do so, said Warren could benefit from sticking out the race a bit longer, in case the rapidly changing picture scrambles once more.


“I have always said we are not going to know what’s happening in this race until the next Tuesday,” Dean said. “If I were Elizabeth, I don’t think I’d drop out until next week.”

But some progressives have begun hinting that Warren’s candidacy is hurting Sanders, who underperformed in some states on Tuesday and now faces a dire threat from Biden.

“Imagine if the progressives consolidated last night like the moderates consolidated, who would have won?” Omar asked on Twitter Tuesday night.

Sanders struck a careful note instead.

When asked about Warren at a Wednesday press conference, he took out a piece of paper and placed it on the top of his lectern, reading from it as he answered the question. “It is important I think for all of us, certainly me who has known Elizabeth Warren for many, many years, to respect the time and space she needs to make a decision,” Sanders said, mirroring Lau’s statement asking for “time and space.”

If history is any guide, Warren may be inclined to wait on an endorsement if she exits the campaign. In 2016, she stayed neutral during the primary between Sanders and Hillary Clinton — even though she was more ideologically aligned with Sanders — and then endorsed Clinton once she was the presumptive nominee.

A Warren endorsement would likely provide Sanders with a much-needed boost as he heads into a slate of contests against Biden.

“It’s certainly possible that her strength among suburban women could help [Sanders] with that demographic and show that he could be something of a unifier,” said Sean McElwee, a progressive pollster who has worked with Warren’s campaign.


McElwee said he believed more of Warren’s remaining supporters leaned toward Sanders over Biden, because those who leaned toward Biden were more likely to have jumped ship already during his post-South Carolina surge.

But Warren has expressed deep skepticism about both Sanders and Biden on the trail, clashing with Sanders over his alleged private comments about a woman not being able to defeat Trump and tangling with Biden after he called her elitist and suggested he had just as much to do with creating the Consumer Financial Protection Bureau as she did. And just in the last few days, she told crowds in Houston and Los Angeles that neither Sanders nor Biden can meet the moment.

Some Sanders endorsers have started reaching out to people in Warren’s camp to talk about unifying and to soothe any bad feelings between the two groups.

Representative Alexandria Ocasio-Cortez tweeted Wednesday that activists should remain positive and welcoming, an attempt to calm any online vitriol from Sanders supporters against Warren that could hinder an endorsement, according to one Democrat familiar with the strategy.

Liz Goodwin can be reached at elizabeth.goodwin@globe.com. Follow her on Twitter @lizcgoodwin Jess Bidgood can be reached at Jess.Bidgood@globe.com. Follow her on Twitter @jessbidgood.