Minnesota Democratic Senator Amy Klobuchar has announced she is running for president in the 2020 election.
Ms Klobuchar, a former prosecutor, said she was running for “everyone who wanted their work recognised”.
She won praise for grilling Supreme Court Justice Brett Kavanaugh and attorney general nominee William Barr during recent confirmation hearings.
The 58-year-old enters an increasingly crowded field of Democrats competing to challenge President Donald Trump.
Ms Klobuchar called on people to join her “homegrown” campaign, saying, “I don’t have a political machine. I don’t come from money. But what I do have is this: I have grit.”
Elizabeth Warren, Kamala Harris and Tulsi Gabbard are among those who have already announced that they will run.
The 2020 Democratic presidential primary will also be the first time that more than one woman has put herself forward for the party’s nomination.
A record total of five women have so far entered the race for the US presidency.
After working as a lawyer in a private firm, she became chief prosecutor for Hennepin, Minnesota’s most populous county, in 1998.
Eight years later, she was elected to the Senate to represent Minnesota – the first woman to get the job.
Ms Klobuchar has long prided herself in her bipartisanship; on being able to, as she wrote in her 2015 memoir, “disagree without being disagreeable”.
“Courage is about whether or not you’re willing to stand next to someone you don’t always agree with for the betterment of this country,” she wrote.
It is this approach that has given her a reputation for being “Minnesota nice” – but it also, in her early years, reportedly earned her the unflattering nickname “Cotton Candy Amy” in some circles.
Analysis by Anthony Zurcher
Her kick-off rally looked like a scene out of the Disney film Frozen, with a snow-covered crowd gathered near the banks of an icy river. Amy Klobuchar’s newly announced presidential campaign, however, could generate some heat in 2020.
She may not have the same level of name recognition as recent and future entrants into the race, but the three-term Minnesota senator has shown the ability to win votes in the kind of Midwestern battleground state that Donald Trump appealed to in 2016.
She offers a steady, sensible political outlook that could attract the majority of Democratic voters who are more interested in electability than ideological purity.
Her buzz has been dampened a bit by recent allegations that she has been abusive toward her staff, but she may try to turn the criticism into a strength.
“I have high expectations for the people that work for me,” she told NBC News after her speech, “but I have high expectations for this country.”
Ms Klobuchar has become a fashionable pick as a “dark horse” candidate. It wouldn’t be a shock if she has a good showing in the neighbouring-state Iowa caucuses and rides that momentum deep into the primary season.
After years under the radar, the former prosecutor went viral last September for her tense exchange with Justice Brett Kavanaugh over his history of drinking.
In January this year, she proved that this frank interrogation style was not a one-off when she grilled President Trump’s attorney general nominee Mr Barr about obstruction of justice allegations.
Meanwhile, former employees of Ms Klobuchar have disputed her “Minnesota nice” image too, telling the Huffington Post that at least three potential campaign managers have withdrawn over her treatment of staff.
In an age when political views are condensed into 280 characters and measured in retweets, Ms Klobuchar’s reputation for working away in the background could help her stand out.
She was able to turn 43 Trump-voting Minnesota counties over to her side in last year’s mid-term elections.
But her bipartisan approach may not stand her in such good stead in a party now dominated by the progressive left.
For example, while she has publicly spoken out against President Trump’s immigration and border policies, she has not voiced her support for the movement to abolish US Immigration and Customs Enforcement (ICE).
Two of her opponents, Kirsten Gillibrand and Ms Warren, have openly called for the agency to be dismantled, while Ms Harris has said it needs to be “critically re-examined”.
She has also avoided supporting Bernie Sanders’ single-payer healthcare bill, known commonly as Medicare for All, preferring to back a “sensible transition” instead.
Many on the left also feel that her education reforms, which push for universities in the US to be more affordable, do not go far enough.
Ms Harris, and likely opponent Mr Sanders, both support making college tuition almost entirely free.