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Sen. Amy Klobuchar sparred in starkly personal terms with some of her main rivals Wednesday night in her testiest performance so far in a Democratic presidential debate.

One of two women left on the debate stage in Nevada, Klobuchar opened by invoking sexism she's faced in the past.

"I have been told as a woman … to wait my turn and step aside. I'm not going to do that," she said, citing a campaign memo by former New York Mayor Michael Bloomberg suggesting that she and other centrist candidates should exit the race.

"I don't think you look at Donald Trump and say we need someone richer in the White House," she shot at Bloomberg.

But Klobuchar's sharpest exchanges were with a leading centrist rival and fellow Midwesterner, former Mayor Pete Buttigieg of South Bend, Ind.

Buttigieg attacked Klobuchar's record on immigration by focusing on her inability in a recent interview to remember the name of Mexican President Andres Manuel López Obrador. Klobuchar attacked Buttigieg for his lack of statewide political success in Indiana.

"I don't think momentary forgetfulness characterizes what I know about Mexico and how much I care about it," Klobuchar said when asked about the lapse. Buttigieg then jumped in to criticize Klobuchar's memory failure, arguing that she had based her whole campaign around her Washington experience.

"Are you saying I'm dumb or mocking me here, Pete?" Klobuchar shot back, precipitating a lengthy and often acrimonious exchange between the two.

Massachusetts Sen. Elizabeth Warren jumped in to defend Klobuchar on that count: "It happens. She forgot the name. It happens to everyone on this stage."

But Warren wasn't always on Klobuchar's side. She incorrectly claimed that Klobuchar's health care proposal is only two paragraphs long, and characterized her approach to fighting climate change as "think smaller."

After Klobuchar touted her record in statewide elections vs. that of Buttigieg, he fired back at her: "If winning the Minnesota Senate translated to winning the presidency, I would have grown up under the presidency of Walter Mondale."

When Klobuchar repeatedly contrasted her work "in the arena" against Buttigieg, he replied: "Maybe leading a diverse city facing economic ruin doesn't sound like the arena to you. I'm used to senators telling mayors that mayors are not as important as senators."

Buttigieg also criticized Klobuchar for her votes to confirm some of Trump's judicial nominees and Cabinet secretaries.

"You've memorized a bunch of talking points," she said, dismissing his criticism. Sparring further with Buttigieg, Klobuchar added, "I wish everyone was as perfect as you, Pete."

Strong performances in the last couple of presidential debates were a driving reason behind Klobuchar's recent bounce in the Democratic presidential race, raising her profile as the campaign looks to parlay momentum from a surprisingly strong New Hampshire finish into the next voting states.

But Klobuchar faced tough questioning from moderators in Nevada, where she was grilled about her tenure as Hennepin County attorney: specifically, the lack of prosecutions of police-involved shootings, and the conviction of Myon Burrell in a shooting case that has since been called into question.

"Why should black and Latino voters trust your judgment now?" moderator Chuck Todd asked Klobuchar.

"I have had the support of African-Americans in my community in every election," Klobuchar said. "I earned it, and this is going to be on me to earn it."

Klobuchar pointed out that charging decisions on police shootings when she was county attorney were made by grand juries.

That has since changed. She also said the current Hennepin County attorney should review new and old evidence in Burrell's conviction.

Despite a recent spike in fundraising and decent poll showings, Klobuchar continues to lag behind poll leaders such as Vermont Sen. Bernie Sanders and a rising Bloomberg.

And the pressure of the race is about to multiply. Following the Nevada caucus on Saturday and the South Carolina primary on Feb. 22, the 14-state Super Tuesday primary comes quickly on March 3.

While Sanders rises in national polls with a clear base in the party's left, Klobuchar and Bloomberg, former Vice President Joe Biden and Buttigieg are battling for the middle. In an NBC News/Wall Street Journal national poll released Wednesday, Klobuchar landed in sixth place behind Sanders, Bloomberg, Biden, Warren and Buttigieg.

As she has before, Klobuchar hit Sanders on his Medicare for All proposal Wednesday night, saying Democrats should strengthen the Affordable Care Act. "When you see troubled waters," she said, "you don't blow up the bridge, you rebuild it."