In a recent interview with the Washington Post, Mass. Senator Elizabeth Warren apologized for identifying herself as Native American for almost two decades.
The apology comes after the Post obtained Warren's 1986 registration for the state bar of Texas, in which she identified herself as "American Indian".
Her office did not dispute the card's authenticity, the paper reported.
In the interview Tuesday, while Warren acknowledges she "can't go back," she says she's sorry "for furthering confusion on tribal sovereignty and tribal citizenship and harm that resulted."
Warren has been trying for the past year to get past the controversy as she considers a run for president in 2020.
Late Wednesday, Warren answered reporters' questions on Capitol Hill, and said she has not called tribal leaders again since the latest development, but said it was her heartfelt apology.
"I haven't spoken with anyone since I saw this information, no, but my apology is an apology for not having been more sensitive about tribal citizenship and tribal sovereignty," Warren said.
Warren ignored a question Wednesday afternoon asking if she was considering dropping out of the race, walking away from reporters after it was posed.
The controversy surrounding Warren's ethnic heritage has long been an issue woven into her political career. In 2012, she was attacked during her Senate race for identifying as Cherokee in order to take advantage of affirmative action.
Despite unsubstantiated claims that she is part 1/32 Cherokee, Warren vehemently stood by her decision to represent herself as Native American for years. Thus far, Warren has only cited "family stories" as a base for her Native American heritage, yet has never been able to name a specific Native American ancestor.
The debate over the veracity of Warren's Native American heritage claims has been kept alive not only by Warren herself but also by right-wing opponents who constantly kept bringing the topic back into discussion. President Trump has since nicknamed her Pocahontas, a gesture many find offensive and has been dubbed as a racial slur.
Presidential historian and author Tom Whalen said the situation could greatly hurt Warren's presidential chances.
"These questions are hanging over on her neck like an albatross," Whalen said. "Character I think still matters among voters. it just shows that her candidacy is flawed, questions and issues."
Last year, Warren released a DNA test she took in order to refute President Donald Trump's taunts about her claim of Native American heritage.
The Native American community derided her decision to take the test, claiming Warren mistook DNA with identity. She has since apologized.
Though Warren's test revealed that she may have Cherokee blood, and though she was told her great-great-great-grandmother was Cherokee, "that doesn't mean the woman was pure Cherokee," Politifact reported.
"Different families and groups interacted in different ways with European settlers in the region," Deborah Bolnick, University of Connecticut professor and past president of the American Association of Anthropological Genetics, told Politifact. "When there was intermarriage, the offspring sometimes became part of indigenous communities, and sometimes they identified with nonindigenous groups."
There aren’t any genetic markers specific to tribal nations, she added. “The genetic patterns don’t map onto tribal groups that we recognize today.”
Warren is expected to make a major announcement about her candidacy for president in 2020 later this week.