She has also signed on to at least six bills directly related to Native American policy. It’s clearly an organized effort: Four of those co-sponsorships came within two days of her speech, and Warren endorsed two bills around that time even though they’d been introduced months earlier.

It comes as Warren considers a run for the White House in 2020. Her Feb. 14 address to the National Congress of American Indians was widely praised by conference attendees, and her allies viewed it as an important step forward for a potential candidate who had faced unexpectedly harsh criticism from both Republicans and some liberal activists over her claims of Cherokee and Delaware heritage despite a lack of documentation — a reality she acknowledged in the speech and her private conversations with Native American leaders.

Now, Warren and her backers are hoping to move beyond the argument entirely and spin it into a positive. The aim is to neutralize what’s seen as an Achilles’ heel for a potential national bid, turning wary activists into allies.

“Her speech was, in many ways, long overdue. It was a great opportunity for her to tell her story,” said Rion Ramirez, chairman of the Democratic National Committee’s Native American Council, who sat down with Warren the day before she addressed the NCAI. “Unfortunately, her president tries to define what her story is. And it’s not his story to tell.”

“It’s ridiculous that a non-Indian man, that’s our president, tries to sit there and define who is and who isn’t Native,” he added.

Still, the sudden flurry of activity on Native American issues opens Warren to accusations that her maneuvers simply reflect a political scramble to mitigate an issue that’s made her vulnerable in the past.

When the first-term lawmaker surprised the NCAI by appearing onstage this month, she acknowledged her own controversy before framing herself as an ally of Native Americans in their fight for fair treatment.

“I get why some people think there’s hay to be made here: You won’t find my family members on any rolls, and I’m not enrolled in a tribe. And I want to make something clear: I respect that distinction, I understand that tribal membership is determined by tribes, and only by tribes. I never used my family tree to get a break or get ahead; I never used it to advance my career,” she said, diving into a personal history that few outside Massachusetts had heard her tell before, and addressing the Pocahontas nickname she has long decried as racist.

“I’m here today to make a promise: Every time someone brings up my family’s story, I’m going to use it to lift up the story of your families and your communities.”

One week before the speech, Warren met with Cheryl Andrews-Maltais, chairwoman of the Wampanoag Tribe of Gay Head, in Massachusetts, who wound up introducing her on stage. The senator also sat down with leaders of the Tribal E-Commerce Coalition, and the day before her address she met with Ramirez, as well as prominent members of the Mille Lacs Band of Ojibwe.

In the ensuing days, she also spoke personally with leadership or prominent members of the Choctaw Nation, the Lac Courte Oreilles Band of Lake Superior Chippewa, and the Suquamish and the Puyallup tribes, as well as Julie Johnson, a prominent activist from Washington state.

The meetings came just as Warren was signing on to a series of bills to help Native Americans. That included a resolution introduced by Sen. Steve Daines (R-Mont.) to commemorate “missing and murdered Native women and girls,” as well as another Daines proposal to grant tribes more resources to combat the opioid epidemic.

Yet some of the legislation she backed had long been in motion: A housing bill led by Sen. Tom Udall (D-N.M.) had been introduced five months earlier, and a bill from Sen. Heidi Heitkamp (D-N.D.) updating an educational program was 10 months old.

The question of Warren’s heritage was a prominent subplot in her successful 2012 bid to unseat Republican Sen. Scott Brown. And it flared up in recent months as Trump, well aware she may challenge him in 2020, repeatedly referred to her using his nickname.

Warren was listed as Native American in law school directories during her career as a professor. She told the NCAI that her parents eloped because her father’s family in Oklahoma was “bitterly opposed” to his relationship with her mother, whose “family was part Native American.” The 68-year-old senator had been surprised by the line of attack when she first ran, though her team maintained that it didn’t resonate as much with voters as Brown apparently believed at the time.

GOP leaders have continued using her claims of Native heritage to make the case that Warren is not who she says she is. They allege she misrepresented herself to get a job at a time that Harvard — where she landed — was struggling with diversity. The Republican National Committee even knocked Warren for not attending NCAI just before she made her surprise appearance.

“Fauxcahontas MIA From Major Native American Summit,” read one email sent by the RNC to reporters, detailing her history of claiming Native ancestry.

It’s not just a Republican attack: Liberal Native American activists have also criticized Warren. They argue she hasn’t gone far enough in explaining her claimed ties to the culture and needs to do more work for their communities. One, Rebecca Nagle, wrote in a November ThinkProgress post, “She is not from us. She does not represent us. She is not Cherokee.”

Still, after the speech, Nagle told The Boston Globe that Warren’s speech was a welcome step, though she still encouraged the senator to dig further into her own background.

The positive responses were welcomed by Warren’s team, who chafed at the “tomahawk chops” Brown staffers performed to rattle her, and Trump’s repeated “Pocahontas” jabs.

“The Brown campaign thought they had a sure winner in 2012, and they failed miserably,” said Guy Cecil, the Democratic strategist who led Senate Democrats’ campaign arm that year and is now chairman of Priorities USA, the party’s largest super PAC. “Elizabeth answered those questions in 2012, and I was glad to see her take the president’s racist attacks straight on.”