Klobuchar tried to carve out space in the Democratic primary field by running on a more moderate platform than many of her rivals and touting her ability to appeal to Midwestern voters. But the third-term senator from Minnesota struggled to gain a foothold in a crowded field despite a flash of early success.

Biden, like Klobuchar, has positioned himself as a pragmatic candidate suited for those uncomfortable with Sanders' sweeping policy proposals. It is unclear whether Klobuchar supporters would be more inclined to support Biden over alternatives such as Sanders, former New York Mayor Mike Bloomberg and Sen. Elizabeth Warren of Massachusetts — though her endorsement could push them in the direction of the former vice president.

The departure of Klobuchar, and former South Bend, Ind. Mayor Pete Buttigieg a day earlier , leaves a chunk of the vote up for grabs across the 14 states holding primaries on Tuesday. Klobuchar and Buttigieg's presence in the race threatened to sap delegates from Biden, who narrowly trails Sen. Bernie Sanders in the national delegate race after four contests.

The Minnesota senator will join her soon-to-be former rival at a rally in Dallas and support his bid for the nomination, a campaign spokesman confirmed. Klobuchar will leave the race a day before her state holds its presidential primary. Minnesota will award 75 national pledged delegates.

Sen. Amy Klobuchar will drop out of the 2020 Democratic presidential race on Monday and endorse former Vice President Joe Biden.

Democratic presidential candidates (L-R) former Vice President Joe Biden and Sen. Amy Klobuchar (D-MN) walk on stage prior to the Democratic presidential primary debate at the Charleston Gaillard Center on February 25, 2020 in Charleston, South Carolina.

Klobuchar focused on issues such as health care and climate change during her presidential bid. As she tried to distance herself from her rivals in recent weeks, she criticized early frontrunner Sanders for his "Medicare for All" plan and Buttigieg for a lack of experience.

After a fifth-place finish in the Iowa caucus, Klobuchar rode a strong debate performance to third in the New Hampshire primary. But she failed to replicate the success in the caucus in Nevada, a state with a more diverse electorate. Polls found Klobuchar generally struggled to gain traction with voters of color.

Indeed, she had another poor showing in the South Carolina primary, where black voters make up the majority of the Democratic electorate. Only 1% of black voters in the Palmetto State chose Klobuchar, according to exit polls.

After a sixth-place finish in Nevada, Klobuchar said her campaign "exceeded expectations" at every turn. She argued she could offer a haven to voters in the middle of the ideological spectrum weary of President Donald Trump's personality and policies.

"Donald Trump's worst nightmare is that the people in the middle, the people who are tired of the mudslinging and the name calling, will have a place to call home this November and that has been our mission from the beginning," the senator said after a sixth-place finish in Nevada.

After Sanders' win in Nevada, some Democrats called for White House hopefuls to drop out of the race so voters uncomfortable with the Vermont senator could coalesce around one alternative. Klobuchar said she would not leave the race then, asking, "Why would I get out?"

Klobuchar narrowly leads recent polls in Minnesota over Sanders. The Vermont senator will hold a rally in St. Paul on Monday night as he makes his final push in the state. Minnesota has early voting, meaning thousands of people chose their preferred Democrat before Klobuchar left the race.

In a tweet Monday congratulating Klobuchar for running a "strong, issues oriented campaign," Sanders said he hoped "her supporters will join us in our fight to defeat Donald Trump in November and win real change."

Bernie Sanders tweet

For most of the primary, Klobuchar failed to keep up with the fundraising pace of the top Democratic candidates. Sanders, in particular, enjoyed success with small-dollar donors.

She did get a boost after the New Hampshire debate, taking in more than $12 million in a week. She bought television ads across multiple states holding primaries on this week's Super Tuesday, when 14 states held nominating contests.

In January, The New York Times endorsed her for president, along with Warren, whose campaign called for more drastic policy changes than Klobuchar did.

But Klobuchar ultimately failed to break into the top echelon of candidates in the vast majority of primary polls.

The senator faced criticism earlier in 2019 for reports that she mistreated Senate staff members. She responded by saying she had "high standards" and was "tough" enough to deal with world leaders.

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