Sioux City, Iowa (CNN) Elizabeth Warren did not wait long to address the question that lingered over her visit to a Native American presidential candidate forum Monday in Iowa.

After thanking New Mexico Rep. Deb Haaland, who had vigorously defended her minutes earlier, the Massachusetts senator quickly addressed her past claims to tribal heritage . Warren had drawn criticism over her decision last year to release the results of a DNA test that showed distant Native American ancestry. In the aftermath of that, she apologized, in public and private.

On Monday, she did so again.

"Like anyone who's being honest with themselves, I know that I have made mistakes. I am sorry for harm I have caused," the 2020 Democratic presidential candidate said. "I have listened and I have learned -- a lot. And I am grateful for the many conversations that we've had together."

The audience had heard enough and applauded as Warren finished her thought and promised to continue her long partnership with Native communities "as President of the United States of America." Over the next 20 minutes, at least two of the questioners onstage would say they hoped for the chance, one day soon, to address her by that title.

Warren's rise in the Democratic primary has been built on a combination of detailed policy plans and her relentless engagement with voters and local leaders. At the Frank LaMere Presidential Candidate Forum here, she leaned on both, again showing off her fluency on the core issue at stake for this audience -- federal policy concerning Native Americans, and the many ways in which the government has let down or betrayed tribes. Warren's release last week of a new suite of policy plans and draft legislation, crafted with Haaland, seemed to speak on its own to many of the questions in Sioux City.

In her introduction, Haaland, who has endorsed Warren, called the media's focus on President Donald Trump's insults -- and the speculation over what they meant for Warren's campaign -- a political gift to Trump.

"Every time they asked about Elizabeth's family instead of the issues of vital importance to Indian country, they feed the President's racism," Haaland said. "Elizabeth knows she will be attacked, but she's here to be an unwavering partner in our struggle, because that is what a leader does."

Photos: Former presidential candidate Elizabeth Warren Photos: Former presidential candidate Elizabeth Warren Elizabeth Warren, a US senator from Massachusetts, speaks during a campaign event in March 2019. Hide Caption 1 of 45 Photos: Former presidential candidate Elizabeth Warren Warren is held by her father, Donald Herring, soon after she was born in Oklahoma City in 1949. "My daddy worked hard his whole life," Warren said when she posted this picture to Facebook on Father's Day 2014. "He sold fencing and carpeting, and ended up as a maintenance man. He and my mother never had much, but he said that his life was a success because his four kids had more opportunities than he had." Hide Caption 2 of 45 Photos: Former presidential candidate Elizabeth Warren A young Warren sits with her mother, Pauline. "When I was 12, my daddy had a heart attack," Warren wrote on Facebook in 2017. "All three of my brothers were off in the military, and Daddy was out of work for a long time. We lost our family station wagon, and we were about an inch away from losing our home. One day, I walked into my mother's room and found her crying. She said, 'We are not going to lose this house.' She wiped her eyes, blew her nose, and pulled on her best dress -- the one she wore to funerals and graduations. At 50 years old, she walked down the street and got her first paying job: answering the phones at Sears. That minimum wage job saved our home, and my mother saved our family." Hide Caption 3 of 45 Photos: Former presidential candidate Elizabeth Warren Warren poses for a Christmas photo with her brother John. All three of her brothers served in the military. Hide Caption 4 of 45 Photos: Former presidential candidate Elizabeth Warren In the late 1960s, Warren attended George Washington University on a debate scholarship. She dropped out after two years to get married, but she graduated from the University of Houston in 1970. Hide Caption 5 of 45 Photos: Former presidential candidate Elizabeth Warren Warren holds her newborn daughter, Amelia, in 1971. She and her first husband, Jim Warren, had two children before divorcing in 1980. Hide Caption 6 of 45 Photos: Former presidential candidate Elizabeth Warren Warren with her three brothers -- Don, John and David -- in 1980. After graduating from college, Warren worked as a speech pathologist at a New Jersey elementary school. She then got a law degree and taught at the Rutgers School of Law before becoming a professor at the University of Houston Law Center. She's also been a professor at the University of Texas Law School, the University of Pennsylvania Law School and Harvard Law School. Hide Caption 7 of 45 Photos: Former presidential candidate Elizabeth Warren Warren and her second husband, Bruce Mann. She posted this old photo to Facebook in 2016 along with a story about how she proposed to him. They were married in 1980. Hide Caption 8 of 45 Photos: Former presidential candidate Elizabeth Warren Warren teaches at the University of Pennsylvania Law School in the early 1990s. Hide Caption 9 of 45 Photos: Former presidential candidate Elizabeth Warren US Sen. Barack Obama listens to Warren speak during a roundtable discussion about predatory lending in 2008. Warren is an expert on bankruptcy law and was an adviser to the National Bankruptcy Review Commission in the 1990s. In 1989, Warren co-authored the book "As We Forgive Our Debtors: Bankruptcy and Consumer Credit in America." Hide Caption 10 of 45 Photos: Former presidential candidate Elizabeth Warren Warren takes her seat to testify before the House Budget Committee in 2009. The United States was battling a recession at the time, and Warren had been appointed to a congressional oversight panel overseeing the $700 billion Troubled Assets Relief Program. Hide Caption 11 of 45 Photos: Former presidential candidate Elizabeth Warren Warren and Treasury Secretary Timothy Geithner listen to President Barack Obama at the White House in September 2010. Obama was appointing Warren to be his assistant and special adviser to the Treasury Secretary in order to launch the Consumer Financial Protection Bureau. Warren had long called for a federal agency designed to protect consumers from fraudulent or misleading financial products. Hide Caption 12 of 45 Photos: Former presidential candidate Elizabeth Warren Warren and US Sen. Scott Brown, right, make fun of each other during an annual St. Patrick's Day breakfast in Boston. Warren announced in 2011 that she would be challenging Brown for his Senate seat.. Hide Caption 13 of 45 Photos: Former presidential candidate Elizabeth Warren Warren speaks to constituents at a campaign event in Scituate, Massachusetts, in May 2012. Hide Caption 14 of 45 Photos: Former presidential candidate Elizabeth Warren Warren takes a morning walk with her dog Otis on the Harvard University Business School campus in May 2012. Hide Caption 15 of 45 Photos: Former presidential candidate Elizabeth Warren Warren stands with family members after giving a speech in Springfield, Massachusetts, in June 2012. Warren has several grandchildren. Hide Caption 16 of 45 Photos: Former presidential candidate Elizabeth Warren President Barack Obama greets Warren at a fundraiser in Boston in June 2012. Hide Caption 17 of 45 Photos: Former presidential candidate Elizabeth Warren Warren speaks at the Democratic National Convention in September 2012. Hide Caption 18 of 45 Photos: Former presidential candidate Elizabeth Warren Warren greets supporters during a campaign event at Boston University. Hide Caption 19 of 45 Photos: Former presidential candidate Elizabeth Warren Warren takes the stage after defeating Brown for a Senate seat in November 2012. Hide Caption 20 of 45 Photos: Former presidential candidate Elizabeth Warren Warren listens during a hearing of the Senate Committee on Banking, Housing and Urban Affairs in May 2013. Hide Caption 21 of 45 Photos: Former presidential candidate Elizabeth Warren Warren meets with Supreme Court nominee Merrick Garland in April 2016. Hide Caption 22 of 45 Photos: Former presidential candidate Elizabeth Warren Warren campaigns with Democratic presidential candidate Hillary Clinton in June 2016. Hide Caption 23 of 45 Photos: Former presidential candidate Elizabeth Warren Warren, a member of the Senate Banking Committee, questions Wells Fargo CEO John Stumpf in September 2016. Warren unleashed a verbal barrage at Stumpf, calling the embattled bank boss "gutless" and demanding he step down. Her diatribe was the most forceful condemnation yet of Wells Fargo, who fired more than 5,000 employees over the years for creating fake accounts without customer knowledge. The employees created the fraudulent accounts to meet bank quotas and were allegedly threatened with firing if they didn't comply. Hide Caption 24 of 45 Photos: Former presidential candidate Elizabeth Warren In January 2017, Warren posted this photo of her and Obama together. Obama was leaving after two terms as President. Hide Caption 25 of 45 Photos: Former presidential candidate Elizabeth Warren Warren holds a transcript of her speech in the Senate Chamber after she was cut off during the debate over Attorney General-designate Jeff Sessions in February 2017. In an extremely rare rebuke, Senate Majority Leader Mitch McConnell silenced Warren after he determined that she violated a Senate rule against impugning another senator. Warren was reading from a 1986 letter in which Coretta Scott King, the widow of Martin Luther King Jr., was critical of Sessions -- who at the time was a nominee to be a federal judge. Hide Caption 26 of 45 Photos: Former presidential candidate Elizabeth Warren Warren and other Democrats listen as President Donald Trump speaks to a joint session of Congress in February 2017. Hide Caption 27 of 45 Photos: Former presidential candidate Elizabeth Warren US Sen. Bob Corker talks with Warren during a Senate committee hearing in June 2017. Hide Caption 28 of 45 Photos: Former presidential candidate Elizabeth Warren Warren attends a confirmation hearing for Jerome Powell, who was nominated to be chairman of the Federal Reserve, in November 2017. It was a day after President Donald Trump referenced Warren as "Pocahontas" during an event honoring Navajo code talkers. Conservatives have long criticized Warren for claiming that she is part Native American, and the senator's heritage became an issue during her Senate campaigns. Trump seized on the attacks and has regularly mocked Warren by calling her "Pocahontas." In October 2018, Warren released results of a DNA test showing she has distant Native American ancestry. The DNA results claimed "strong evidence" of Native American ancestry "6-10 generations ago." But it only served to intensify the criticism given her distant ties. Hide Caption 29 of 45 Photos: Former presidential candidate Elizabeth Warren Warren runs down Boston's Clarendon Street waving to crowds during the annual Boston Pride Parade in June 2018. Hide Caption 30 of 45 Photos: Former presidential candidate Elizabeth Warren Warren and US Sen. Susan Collins ride the Senate subway in June 2018. Hide Caption 31 of 45 Photos: Former presidential candidate Elizabeth Warren Warren is seen in the sunglasses of Arian Rustemi during a rally in Boston in June 2018. Warren was calling for the swift reunification of children and parents who had been separated at the US-Mexico border. Hide Caption 32 of 45 Photos: Former presidential candidate Elizabeth Warren Warren helps Georgia gubernatorial candidate Stacey Abrams make calls to voters in October 2018. Hide Caption 33 of 45 Photos: Former presidential candidate Elizabeth Warren A Warren figurine sits in the back pocket of Mary Jo Kane during a town-hall event in Boston in October 2018. Hide Caption 34 of 45 Photos: Former presidential candidate Elizabeth Warren Warren was re-elected in 2018. Here, she is joined by her husband, Bruce Mann, as Vice President Mike Pence re-enacts her swearing-in. Hide Caption 35 of 45 Photos: Former presidential candidate Elizabeth Warren Warren, her husband and dog Bailey attend an event in Manchester, New Hampshire, in January 2019. Warren had recently announced that she was forming an exploratory committee for the 2020 presidential race. Hide Caption 36 of 45 Photos: Former presidential candidate Elizabeth Warren Warren speaks in Columbia, South Carolina, in January 2019. Hide Caption 37 of 45 Photos: Former presidential candidate Elizabeth Warren Warren looks down at the crowd in Lawrence, Massachusetts, before formally announcing her presidential bid in February 2019. Hide Caption 38 of 45 Photos: Former presidential candidate Elizabeth Warren Warren answers questions at a town-hall event in Jackson, Mississippi, in March 2019. Hide Caption 39 of 45 Photos: Former presidential candidate Elizabeth Warren Warren makes a pinky promise with 8-year-old Sydney Hansen during a campaign stop in Peterborough, New Hampshire, in July 2019. Hide Caption 40 of 45 Photos: Former presidential candidate Elizabeth Warren US Sen. Bernie Sanders grabs Warren's hand during the CNN Democratic debates in July 2019. Sanders and Warren, two of the most progressive candidates in the field, were targeted early in their debate by their more moderate counterparts. Hide Caption 41 of 45 Photos: Former presidential candidate Elizabeth Warren Warren speaks at her Super Tuesday rally in Detroit in March 2020. Hide Caption 42 of 45 Photos: Former presidential candidate Elizabeth Warren Warren acknowledges supporters as she arrives to speak to the media outside her home in Cambridge, Massachusetts, in March 2020. She had just dropped out of the presidential race. Hide Caption 43 of 45 Photos: Former presidential candidate Elizabeth Warren Warren appears on "Saturday Night Live" with actress Kate McKinnon, playing Warren, in March 2020. "I wanted to put on my favorite outfit to thank you for all you've done in your lifetime," McKinnon said. "I'm not dead," Warren responded. "I'm just in the Senate." The two then said the show's famous catchphrase, "Live ... from New York! It's Saturday night!" Hide Caption 44 of 45 Photos: Former presidential candidate Elizabeth Warren Warren asks questions during a Senate committee hearing in June 2020. She was appearing via video conference because of the coronavirus pandemic. Hide Caption 45 of 45

Both the leaders up on stage and the audience seemed to agree. Warren was greeted warmly and she cycled seamlessly between notes of empathy and her case for the "structural change" needed to benefit and revive Native communities. She talked about directing new resources to tribes and guaranteeing them broader jurisdiction on their own lands. On the question of missing and murdered indigenous women -- and men, Warren noted -- the issue needs more attention from the government and the national media, she said.

"A problem that is not seen," she said, "is a problem that is not fixed."

Manape LaMere, son of the late Frank LaMere -- the activist after whom the conference is named, told CNN after Warren spoke that he appreciated her focus on policies important to Native people.

"I hope that people can pay attention to what she's saying about her policies -- she seems to have a pretty, pretty good pulse on at least the legal understanding," LaMere said.

As for Warren's mea culpa for her handling of her own family's ancestry, LaMere said he accepted the apology and that he was not interested in discussing it further: "We all make mistakes and if we're able to hold ourselves accountable to people, that's fine. That's what we're supposed to be doing."

The conference -- and the fact that several top-tier presidential candidates are attending it this week -- was his father's dream, LaMere added.

"We're forgotten and so I loved to see how Dad has encouraged us to come together and we're checking off a dream," he said. "Posthumously, we're checking off a dream of his."

The desire to see Native issues given more attention was a consistent message across the morning and into the afternoon.

After Warren's session, Aric Armell, who came to Sioux City from his home in Winnebago, Nebraska, where he is an enrolled tribal member, said the forum was just a beginning. He wanted to hear more from Warren -- and all the candidates -- and not just at a one-off event.

"A lot of the topics that came up don't normally get a chance to come out. For a lot of the candidates today, for them to speak on that, it was really good to hear," Armell said.

Warren, he added, seemed to have "skimmed over" the issue of her ancestry. But Armell wasn't too bothered. Like so many others here, he was looking farther down the road.

"I think what she had to say is really good for Indian country. Her track record speaks to all that," he said. "If she's the president, we've got a good foundation with her already."