Amy Klobuchar stood in the shadow of Selma's historic Brown Chapel AME Church. On a warm, sunny Sunday, just two days before Super Tuesday, she joined several Democratic rivals for a unity march across the Edmund Pettus Bridge to commemorate Bloody Sunday, the 1965 civil rights march that turned violent when unarmed demonstrators were attacked.

With civil rights legend John Lewis speaking, she noticed former South Bend, Ind., Mayor Pete Buttigieg choking up just a few feet away. Both had finished out of the medals in the South Carolina primary the day before. She wondered what was going through his mind. There, in the calm of the Alabama chapel, the Minnesota Democrat had a rare moment to reflect on her own standing in the tumultuous race for the White House.

"I was in that church in Selma that morning, and I was thinking, what is better here?" she recalled in a televised interview this week. "What is better for the country?"

The answer, she decided, was becoming clear.

Earlier that day she had begun conversations with her campaign manager about ending her long-shot bid for the White House and backing former Vice President Joe Biden. Despite a third-place finish in New Hampshire weeks before, her path to the nomination was narrowing. A distant sixth-place finish in Nevada's Feb. 22 caucuses hadn't helped.

"She was always in it to win it, but she's also a practical person," said U.S. Sen. Tina Smith, a close friend who traveled with Klobuchar to a campaign rally in Fargo the day after Nevada. "She was quite focused on what happened in Nevada, what there was to look forward to in South Carolina, and also very focused on the dynamic and the relationships between all the Democratic candidates."

Amid private deliberations, the campaign gave no outward sign of slowing down. In the eight days that followed Fargo, she visited nearly a dozen states and held fundraisers to fuel the campaign. Even after her sixth-place finish in South Carolina, she insisted she was still a contender.

"I am still in the top five vote-getters for the country" she said in an interview with WCCO Sunday morning. "And I think that matters."

Still, pressure was mounting as leaders in the Democratic establishment scrambled to blunt the momentum of Vermont Sen. Bernie Sanders, a self-described democratic socialist many feared would drag the party down in November. Biden had just trounced the field in South Carolina, solidifying moderate support. Behind the scenes on Sunday morning, Klobuchar's closest advisers began laying out her options.

"She made the determination that she thought she should get out, and then it was, what's the most impactful way we could do it and be helpful to the vice president?" said campaign manager Justin Buoen. "So the choices were, do we stay in and win Minnesota? Or should we endorse and be supportive of the vice president right away?"

Even within Klobuchar's circle of closest confidants, views on the best path forward differed. She told "CBS This Morning" that her husband, John Bessler, wanted to keep going. Internal polling showed a double-digit lead ahead of Minnesota's March 3 primary.

Competing could allow her to win at least one state in a bid that had already lasted longer than many pundits predicted. Some argued that staying in until Wednesday would help Biden, by denying Sanders needed Minnesota delegates. But it also carried risk: A potential loss to Sanders in Minnesota would be a devastating blow.

"The determination she made was this wasn't a vanity play for her, it wasn't about winning Minnesota," Buoen said. "She wanted to bring the country together and the Democratic Party together and get behind who she thought was the best person to beat Trump."

Klobuchar told NBC's "Today" show that there "literally was no push from anyone" to leave the race. Local aides to the Biden campaign said the same. "Absolutely not," said Corey Day, Biden's Minnesota state director. "There was no pressure."

Insiders also said Klobuchar made the call herself. "I know Amy very well, and ultimately, she considered all aspects and she personally concluded that this is the way to proceed," said Minneapolis attorney Sam Kaplan, a former diplomat and Democratic donor who backed her bid.

As conversations about the campaign's future continued on Sunday, Klobuchar boarded a plane home for a rally in St. Louis Park. Hundreds of supporters sporting green "Amy" stickers and signs filed into a high school gymnasium for the 8 p.m. event.

But the homecoming turned sour. Dozens of demonstrators stormed the stage to protest what some activists say was the wrongful conviction of a black teen sentenced to life in prison during her time as Hennepin County attorney. Top aides tried to broker a deal with the protesters to allow the senator to speak, but to no avail. By 8:45 p.m., the event was canceled. Klobuchar had left the building.

Monday was supposed to be another full day of campaigning ahead of Super Tuesday, with stops planned in Salt Lake City, Denver and Tulsa, Okla. But by 6 a.m. Buoen was on the phone with the Biden campaign. Less than 24 hours after Selma, the decision had been made. "I asked if they wanted our support. They said they did, and we worked it through from there," he said.

Publicly, signs of a shift began to emerge. A reporter in California tweeted that Klobuchar had canceled a planned interview. Top campaign aides went silent on social media.

Hundreds of supporters were already waiting to hear the senator speak at a morning rally at a popular concert venue near the Utah State Capitol. Joel Briscoe, a Democratic state legislator who introduced Klobuchar to the crowd, said the mood seemed upbeat. He joked to a staffer that if the campaign didn't work out, he hoped a vice president slot would be on the table. The aide quipped back: She's in it to win it all.

Klobuchar took the stage about 9 a.m., riffing on the stump speech she'd given countless times. Reporters who had followed her on the trail sensed something was off. The senator, who had mastered a crisp, zinger-filled speech, seemed to meander. According to CNN, she left without pausing for her usual photo line.

It was the last speech of her presidential campaign. Soon after, she broke the news to her staff. Instead of flying to Denver for her next event, she joined a conference call thanking everyone for their work and dedication. She reminded them of the political headwinds, her limited name recognition, the limited resources. "She wanted everyone to know how proud she was and what a special experience it was," Buoen said. "It was very touching. Very sweet."

Just after noon on Monday, the campaign went public: 386 days after she announced her bid in a blizzard on the banks of the Mississippi River in Minneapolis, Klobuchar was suspending her campaign and endorsing Biden.

Hours later the two were on a stage together in Dallas. "I cannot think of a better way to end my campaign than joining his," she told the crowd. Earlier, Buttigieg, who had ended his bid the night before, also appeared with Biden.

The gambit would pay off on Super Tuesday. Biden, who had not campaigned in Minnesota, upset Sanders by a commanding margin. Klobuchar, watching the results from home, got a call from the vice president thanking her for the help. Two thousand miles away, Biden addressed supporters from a stage in Los Angeles.

"We won Minnesota," he said, "because of Amy Klobuchar."

Torey Van Oot • 651-925-5049

Briana Bierschbach • 651-925-5042

Patrick Condon • 202-662-7452