LAS VEGAS — It was debate day, and on the 33rd floor of the grand Bellagio hotel, high above a city of spectacle and risk, Senator Elizabeth Warren was ready to pray.

It was a ritual she and her husband had developed with the Rev. Miniard Culpepper before every presidential debate. But that day in February, with Warren seemingly in need of a miracle to revive her campaign, the minister donned his lucky blue suit and prefaced his regular prayer with a rap.

“Look around see what you see: a lot of old boys who begin with a ‘B.’ A Bloomberg, a Buttigieg, a Bernie, a Biden. When the Big E gets going, they’ll all be a-hiding,’’ Culpepper recited, as Warren threw her head back and laughed, still hoarse from a cold that had all but silenced her earlier in the week.

“She’ll give it right back if you know what I mean,’’ Culpepper continued. “That old boys network is not what it seems.’’

Some of those boys had just bested her in Iowa and New Hampshire, and Warren and her team were disappointed. She was a star among the Democratic Party’s progressive wing, roundly praised for her bold proposals, stamina, and ground game, but it just didn’t seem to be working.

Aware of a meek debate performance in New Hampshire not two weeks before, Warren went into the Las Vegas debate with her brass knuckles on, intent on destroying one member of Culpepper’s “boys network’’ she had no qualms eviscerating.

Just before she went on the debate stage, Warren turned to a senior adviser: “How are you feeling?’’

“I feel like punching Michael Bloomberg in the face,’’ he responded.

“Me too,’’ she said cheerfully.

And so she did, rhetorically speaking. Her blockbuster takedown of Bloomberg turbocharged her fund-raising and offered a glimpse of a different candidate, an uncensored billionaire-slayer who told crowds she was a born fighter.

It’s a performance that brought her immense pride. But it wasn’t enough to save her candidacy.

Two weeks and two more election losses later, Warren was alone with a couple of staffers — and a reporter for The Boston Globe — in a brick-walled room in Detroit’s Eastern Market, the cheering of 2,000 supporters awaiting her appearance coming through the wall. It was Super Tuesday, and the polls would close in several hours. She didn’t know then how bad it would be, how even her home state would choose two of the old “B’’ boys over her. But she seemed to know her chance to transform the race — and the country — was slipping away.

“It’s a little like thinking, ‘Wait, I have all the pieces,’’’ Warren said then. “‘I’m not quite sure why this didn’t come together.’’’

Post-mortem begins

The post-mortem of Warren’s presidential campaign is already underway following the campaign’s end on Thursday. Some supporters wonder where the Bloomberg-slaying version had been all along, lamenting what could have been had her fighter persona been fully unleashed. Others questioned her advertising strategy in Iowa, or her decision to focus on “unity.’’ Staffers grappled with how, in their minds, the best candidate, the strongest team, and best policies did not translate into more votes, admitting she was squeezed between the center and the left.

Warren herself, who is not a brooder by nature, reflected on what was happening in a series of behind-the scenes interviews with the Globe in the final month of her campaign, on the condition they not be used until her bid for the nomination ended, either in victory or defeat.

Though galvanized by her interactions with voters and motivated by her agenda until the very end, Warren ultimately had to reckon with the fact that all her meticulous planning and execution could not win the Democratic nomination. And in order to execute the plans, you have to win.

“We’ve had great and enthusiastic crowds. We’ve had a wonderful team on the ground in each of those states. We have good people, and I believe that I’m fighting for the right values and the right plans,’’ Warren said that night in Detroit, in the last hours of her candidacy.

Many of her supporters believe her gender played a role in her downfall — an issue she rarely brought up in Globe interviews but one her advisers thought about constantly. When she did go on the attack, Warren faced critiques in the media that angered her team.

Her top adviser, Joe Rospars, said on Twitter that Warren faced a double standard as a woman that was “rage inducing.’’ Aides said having to think about mitigating sexism permeated everything they did — from design choices to debate strategy.

Warren knew her exit would leave Democrats with just two options: Vermont Senator Bernie Sanders, a 78-year-old democratic socialist whom she views as ineffective, and former vice president Joe Biden, a 77-year-old who once told a roomful of donors that he didn’t plan to fundamentally change anything as president. It wasn’t just all the pinkie promises Warren made to young girls that a woman can be president. She had concerns about these men as leaders.

As she waited to go onstage in Detroit, still hours away from a reckoning with voters in 14 states and two days from dropping out, Warren worried about the man who is in many ways her political opposite — unscripted, spontaneous, and gaffe-prone — but whose performance would put him in position to win the Democratic nomination.

“A country that elects Donald Trump is a country with serious problems,’’ Warren said. “When I hear vice president Biden talk about restoring this country to what it was, a country that for decades has left a lot of people behind, I worry.’’

She ticked off the ways a candidate with less transformative ideas might fall short: What would happen to student loan debt? Or her dream of universal child care?

At one point in the Detroit interview, she stopped herself, perhaps realizing that she sounded like she cared more about those ideas than actually winning.

“The part of the fight that deeply engages me is the part about change, and, look, I want to win,’’ Warren said. “Of course it matters. If you don’t win, you can’t — you won’t have the tools to make the changes.’’

An Iowa setback

Back in February, Warren still had a chance at making those changes.

Her political fortunes had changed drastically since the heady days of fall 2019, when she was atop most polls and drew 20,000 at a rally in Washington Square Park in New York. Pete Buttigieg, the 38-year-old wunderkind of the race whose rise particularly irked Warren staffers, had leapfrogged her in Iowa polls, after a spirited bashing of her Medicare for All plan. Then, Trump’s impeachment trial marooned her in Washington.

But Warren still hoped that Iowa, where she had drawn large crowds with her populist economic vision and Oklahoma-heavy personal story, could be a springboard to the nomination. She invested heavily there, her campaign even taking out a line of credit in January as her giant field operation racked up costs. Advisers had finally convinced Warren to skip her time-consuming “selfie’’ lines in the final days, allowing her to pack in a few more events. The night before the caucuses, a leaked Des Moines Register poll showed her in second, behind Sanders.

As Iowans gathered to make their choices, Warren and her family waited in a holding area in a Des Moines banquet center. She tried to distract herself by exchanging silly Snapchats with her teenage granddaughter Lavinia, but it was hard to ignore the silence where there should have been results. She finally switched off the TV after mistaking old polling numbers scrolling on the screen for actual results. “This is crazy, I don’t need to look at that,’’ she said.

Warren snapped to attention when her son, Alex, said, “Whoa’’ in an ominous tone as he looked at news on his phone and then fell silent. “You can’t do that,’’ Warren told him. “Either say something out loud or turn your phone off!’’

Her campaign manager, Roger Lau, walked back and delivered the news. Vote counting was going slowly, he said; there would be no results tonight. But, the campaign’s internal numbers had her in a disappointing third place. She should just go ahead and give her speech.

Warren shoved her feelings aside, as disappointment began to wash over many of her staffers.

“It’s a little like asking a patient how you feel during surgery,’’ Warren said of her own response to the night of confusion. “There’s nothing more to do at that point.’’

As she spoke to the waiting crowd, backstage a top aide frantically tried to find her speech on live TV. Instead, most of the cable news networks were featuring Biden, who was on track to place well behind her.

After Warren left the stage, Buttigieg and Sanders both essentially declared victory, despite the lack of results. But Warren appeared calm. She swapped out her jacket for a hoodie, cracked open a beer, and snacked on potato skins. She was far more chipper than one would expect of a candidate who had banked a year of her life on winning Iowa. But she had another chance, and within a couple of hours, she had touched down in Manchester, N.H.

‘OK, what happened?’

Perhaps the most enduring image of Warren in New Hampshire will be her standing on the debate stage, silently, with her hand up.

She had spent the day in a La Quinta Inn conference room practicing the drills she does before debates, her advisers rapidly grilling her with sample questions.

Debates were always harder for Warren than she let on, her advisers said. A former high school debate champion who became a candidate who exuded competence, Warren seemed to be graded on a curve. Biden could ramble or Sanders could seem obstinate, but for her, they thought, anything less than an A+ would always look like a B.

They knew she needed a boost. Buttigieg and Minnesota Senator Amy Klobuchar were drawing headlines and crowds while Warren was pitching herself as a “unity candidate’’ who could fuse a party cleaved by ideological division. But that soft-edged message was drowned out on the rowdy debate stage.

“I’ve been listening to other candidates snarling and biting and bickering for a whole week, and I didn’t think it was helping the Democrats,’’ she said later.

That night, Klobuchar stood out for tearing into her male rivals and making the case for herself. When it was over, Warren’s staff knew she had faded, and whisked her to the spin room to get her back on TV.

On election night in New Hampshire four days later, Warren waited alone with her husband, Bruce Mann, backstage at a sports center. Her campaign had set up what was supposed to be a victory party on an indoor tennis court, where supporters nibbled on meatballs garnished with orchids.

When her senior staffers entered the room, she saw it on their faces. “OK,’’ she asked, “what happened?’’

Warren was trailing Sanders and Buttigieg. Crushingly, she was 10 points behind Klobuchar, too. Her aides told her that they made 1 million house calls, but it wasn’t enough. Then one of them pointed out something else: Klobuchar had simply had a good debate.

Warren’s shoulders slumped. The candidate who always strove for excellence, and who worried more than anything about letting down the people who believed in her, felt like she hadn’t done her job, according to one aide. After that, Warren had a new spark in her, a determination not to let that happen again.

A fighter in Las Vegas

It was practically a different candidate who stepped off the Las Vegas debate stage a week and a half later, a woman who had dismantled Bloomberg’s presidential ambitions.

She asked her staff how it looked from backstage, where one aide noticed that Bloomberg’s Wikipedia page had already been updated to note her evisceration of him.

The debate offered a glimpse of a candidate whose no-holds-barred questioning of corporate villains in congressional hearings had made her a fearsome darling of the left, but who had spent much of the campaign making the affirmative case for her big ideas and telling folksy stories about her brothers while flanked by her golden retriever. In Las Vegas, she didn’t just go after Bloomberg, but also made the clearest case yet for why she was a better candidate than everyone else on stage, one by one. Where had that Warren been all along, some supporters wondered.

Her previous caution reflected a core challenge the campaign believed it faced from day one: Voters’ fears about electing a woman in the wake of Hillary Clinton’s 2016 loss and a double standard in how female candidates are received by voters and the press. For months, Warren’s brain trust had reckoned with her being perceived differently than male candidates; she had faced fierce blowback when she tangled with Buttigieg, and later Sanders, on the debate stage.

She talked often with a top female aide in private about her concerns around gender, but Warren was well aware that doing so publicly was a “trap’’ — you either sounded like a whiner or like you were delusional. One aide said her views on sexism in society appeared to evolve over the course of the campaign, given that she belonged to a generation of women who were told to block out the noise and suck it up to succeed professionally.

“You can’t pull the pieces apart. I am who I am,’’ Warren said on her press bus in New Hampshire in a rare public comment on the issue during the race. “I don’t know what the effects are, but what I do know is that I just have to keep fighting.’’

After Warren threw that straitjacket off in Las Vegas, she was greeted with an outpouring of support. The campaign raised tens of millions of dollars, and thousands again cheered Warren at rallies, going wild when she mentioned her debate performance. Suddenly, she had momentum.

But it was short lived. When Warren went to vote in Cambridge on Super Tuesday, a man stopped her to thank her for being in the race on behalf of his 6-year-old daughter, who he said could not understand why there’s never been a woman president.

“I don’t want to have to explain that to her,’’ Warren told him.

The last selfie line

The last selfie line of Warren’s campaign was on Thursday, a cathartic, chaotic bear hug of the candidate by her staff at her Charlestown headquarters. Some had already broken out the spiked seltzer and Michelob Ultra, Warren’s beer of choice, when she arrived. Pumping her fists and wiggling her hips, a candidate who had just told the world she was dropping out worked her way from desk to desk, pod to pod, thanking the staffers whose work had changed the shape of the race

At one point, she smiled for a selfie with a staffer who was bawling. A few minutes later, she lingered in a tight embrace with speechwriter Chris Huntley, as tears streamed down his face. “I’m not leaving you. Are you leaving me?’’ Warren asked.

“No,’’ he answered. “We’ve got stories to tell.’’

Warren wasn’t a candidate anymore, but she worked the room, still talking about her plans, extolling her Blue New Deal or the way data can inform policymaking.

They mourned what couldn’t be but reveled in what they had achieved — including using the stories of women to stick a knife in Bloomberg’s campaign, which she had outlived by two days. Warren laughed as she embraced a staffer clad in a T-shirt that echoed her most famous debate line: “Fat broads and horse-faced lesbians against billionaires.’’

“You know,’’ Warren said mischievously, “I still get people who come up to me in selfie lines who say, ‘I’m a fat broad!’’’

The next room broke out into a massive cheer of “Bruuuuuce’’ for Warren’s husband.

“Thank you for the mercy chant,’’ Bruce Mann responded softly. “The last 14 months for Elizabeth and me and for all of you have been transformative. We will never be the same.’’

There were more pictures to take, and, for their dog, Bailey, a burrito to steal. And then it was time to go home as the campaign closed up shop, leaving behind a slew of big ideas that she still believes amount to a road map for change.

Jess Bidgood can be reached at Jess.Bidgood@globe.com. Liz Goodwin can be reached at elizabeth.goodwin@globe.com