Sen. Amy Klobuchar (D-MN) suspended her presidential campaign on Monday after failing to turn one flash of success—a third-place finish in the nation’s first primary—into any sustainable momentum in the Democratic nominating contest. She is planning to endorse former Vice President Joe Biden in an event on Monday, one day prior to a slate of states holding presidential primaries.

An aide confirmed that the senator would be "flying to Dallas to join Vice President Biden at his rally tonight where she will suspend her campaign and endorse the Vice President.” She broke the news on a call with staff earlier in the day.

Klobuchar was always a long shot. Having failed to attract as much attention as Sen. Bernie Sanders (I-VT) or several other top-tier contenders, the Minnesota Democrat consistently registered in the low single digits in most early state and national polls. But she hung in the primary race longer than her better-known Senate colleagues, like Sen. Kamala Harris (D-CA), and managed to capitalize on a muddled Iowa caucus—in which she placed a disappointing fifth—with a surprising third-place finish in New Hampshire.

After receiving some of her biggest crowds and highest fundraising totals following the Feb. 11 primary, Klobuchar found a reason to plow forward, cheerfully saying, “we’ve gone up to No. 3!” just before her strong showing. But she largely skipped out on the following two voting states, Nevada and South Carolina, and aimed straight for Super Tuesday, where the bulk of the delegates are up for grabs.

While some may have been surprised at Klobuchar’s longevity in a crowded, contentious race, those who have known the Minnesota senator for decades say it’s hardly shocking. One of the senator’s strongest traits, her allies routinely say, is her abundance of caution, and her ability to make political calculations around it. In 2020, they say, it paid off.

The hype around former South Bend Mayor Pete Buttigieg’s rise from obscurity to national prominence in this primary, said a Minnesota-based Democratic operative, “is true for Amy too, but also backwards and in heels.”

“She may not have risen to the same heights, but she went from sort of an open secret as a talented politician to proving it a few times on the national stage,” said the operative, who spoke anonymously to speak candidly about Klobuchar.

That Klobuchar’s campaign endured so long impressed longtime associates—even those who back other candidates. “She’s in contention,” said Keith Ellison, the Minnesota attorney general and former congressman, “because she’s a pretty damn good politician.”

The senator's reputation for caution spilled into her campaign style. As her progressive rivals, Sanders and Sen. Elizabeth Warren (D-MA), pushed for Medicare for All and free public college tuition, Klobuchar often defended her moderate positioning as tough-love honesty—at times with some success—claiming that while her ideas don’t “fit on a bumper sticker,” they are, she said, “the right ones.” And she cast herself as an alternative to the party’s left-wing standard bearers.

“If you want a Democratic nominee who can make our tent bigger, who can make our coalition wider, and our coattails longer, I know you and I will fight for you,” said Klobuchar after her third-place New Hampshire finish. “And if you feel stuck in the extremes of our politics and you are tired of the noise and the nonsense, you have a home with me.”

But that message may have backfired, said the Democratic operative. “Most Americans still don’t know what she stands for—which makes her impact on the race that much more impressive. She was able to do it without a cohesive identity. It also serves as a good explanation as to why she never got to the top tier.”

Heading into Tuesday, Klobuchar often bragged about her widespread electoral success in Minnesota as proof she could win nationwide. She has won three Senate terms in this purple state by considerable margins—including areas President Trump carried in 2016—to fuel her campaign mantra of winning “every place, every race, every time.”

But as Super Tuesday loomed, there were signs Klobuchar faced a potentially embarrassing showing in her home state. While several polls showed her with a lead, Sanders—who won Minnesota’s 2016 caucuses by over 20 points—was close behind. Key liberals in the state, like Rep. Ilhan Omar, had lined up behind Sanders’ bid, and in a sign of strength, the campaign scheduled his final pre-Super Tuesday rally for an arena in St. Paul, the state capital.

In exiting the race early, Klobuchar joins one of her biggest rivals on the sidelines, who left less than 24 hours prior. When former South Bend, Indiana, Mayor Pete Buttigieg announced on Sunday night that he was suspending his bid, Klobuchar tweeted a comment that was viewed by some as throwing shade at the millennial Democrat.

Throughout her yearlong candidacy, Klobuchar made a results-driven case to voters, touting her record in the Senate and moderate sensibilities as a salve for the trying political times exacerbated by the polarizing nature of the Trump presidency. She leaned hard on her Minnesota roots, casting herself as a candidate from the “heartland” who could help Democrats take back the areas they lost to Trump in 2016.

Known for carefully-deployed zingers on the debate stage, Klobuchar was prone to corny jokes and stories on the stump that emphasized her everywoman appeal: frequently told was the tale of her raising money from ex-boyfriends for her early political campaigns. Rarely missing a moment to plug her home state, she relished that she launched her presidential campaign in a Minnesota snowstorm—a visual that first attracted Trump’s attention to her—and told the story often as a point of pride as she made her case to voters.

But the senator, formerly the top prosecutor of Minnesota’s largest county, had a hard time shaking her tough-on-crime past in a primary where issues of racial justice have been front and center. Fresh reporting on her record, particularly an AP investigation that found her office used questionable tactics to put a man behind bars for life, raised new questions—and fueled calls from Minnesota-based civil rights groups for her to drop out. On Sunday night, some of those protesters disrupted a Klobuchar event near her hometown in the Twin Cities suburbs, prompting her campaign to cancel the event.

It was reflective of Klobuchar’s struggle to expand her support beyond white moderates and liberals. In South Carolina, where she pulled in 3 percent of the vote for a distant sixth place, exit polls show she earned 0 percent support from black voters.