Potential cookbook fraud Elizabeth Warren. Photo: Andrew Harrer/2015 Bloomberg Finance LP

Donald Trump gets a lot of attention for saying offensive things about Mexicans, but on Monday, America’s birther-in-chief reminded us that he doesn’t discriminate when it comes to attacking opponents about their ethnic background. In honor of Elizabeth Warren’s first campaign appearance with Hillary Clinton, Trump tweeted that the Massachusetts senator “lied on heritage,” then called her “Pocahontas” in an NBC News interview. “She made up her heritage, which I think is racist. I think she’s a racist, actually because what she did was very racist,” Trump added. “She used the fact that she was Native American to advance her career. Elizabeth Warren is a total fraud.”

As Warren embraced the role of Clinton’s top anti-Trump attack dog in recent weeks, the presumptive GOP presidential nominee has tried to revive the years-old controversy over her supposed Native American roots. And while Trump’s recent attack on a federal judge’s Mexican heritage was so clearly offensive that even House Speaker Paul Ryan called it “the textbook definition of racist comments,” few have leaped to Warren’s defense. Even in a recent report on how Trump’s attacks on Warren have riled Native Americans, the New York Times is vague about the veracity of her claim, saying only that it dates back to her 2012 Senate campaign. The story closes with a quote from a Navajo Republican running for Congress in Arizona, who believes, “I think Donald Trump is within his full rights to make fun of her for it … It is a scandal.”

So is this one of those confounding times when Trump is actually right? Not really, but the issue hasn’t been put to rest because Warren’s heritage is murky. Aside from the obvious racism of Trump repeatedly calling Warren “Pocahontas” or “the Indian,” an extremely thorough investigation of Warren’s background never turned up proof that she committed “fraud” by intentionally lying about being Native American, or that she benefited from claiming minority status. And as the senator recently noted, it definitely didn’t help her get into Harvard:

Get your facts straight, @realDonaldTrump. I didn’t even go to Harvard – I’m a graduate of @UHouston and @RutgersU. — Elizabeth Warren (@elizabethforma) May 26, 2016

The problem is that no one ever found evidence to support Warren’s claim that she is part Cherokee and Delaware either. As the Washington Post explained in September 2012, the issue emerged when Warren was running against incumbent Republican senator Scott Brown:

In late April, the Boston Herald reported that in the 1990s, Harvard Law School — where Warren began teaching in 1992 and was granted tenure in 1995 — touted the Democrat’s Native American background as part of an effort to boost its diversity hiring record. Warren’s campaign said she didn’t bring up her heritage before Harvard hired her and that her background came out through later conversations… … In late May, the Globe reported that Warren acknowledged that at some point after she was hired by Harvard and the University of Pennsylvania, she informed the schools of her Native American heritage. The revelation spurred a new round of questions, since Warren never brought up the fact a month earlier, instead saying she didn’t know why Harvard listed her as Native American. Earlier in the May, a report pointed out that she listed herself as “white” at the University of Texas Law School, prompting questions about consistency.

As Brown slipped in the polls, he used the issue to question Warren’s character. The fact that she couldn’t explain the inconsistencies and only had anecdotal evidence to back up her claims added fuel to the controversy. “These are my family stories,” she said at the time. “This is what my brothers and I were told by my mom and my dad, my mammaw and my pappaw.” Warren said she was told her parents eloped because her paternal grandparents said of her mother, “No. You cannot marry her, because she is part Cherokee and part Delaware.” She also recalled her Aunt Bee lamenting many times that her father (Warren’s grandfather) “had high cheekbones, like all of the Indians do,” but she didn’t inherit them.

In 2012, The Atlantic did a deep dive on Warren’s heritage and found that she is definitely not qualified to become a member of the Cherokee Nation, as both the tribe and the federal government have strict requirements that exclude even some people with well-documented Cherokee ancestry. (At one point, a genealogist from the New England Historic Genealogical Society believed he’d found a marriage certificate that proved Warren’s great-great-great-grandmother was Cherokee, but later, questions were raised about whether the document exists.)

Warren might not even be Cherokee according to her own standard of family lore. When contacted by the Boston Globe in 2012, some members of Warren’s family shared her memories of family members claiming to have Cherokee blood, but other said they never heard anything about having Native American ancestry.

Still, none of this proves that Warren was willfully misrepresenting her background. Genealogists told The Atlantic that believing you have Native American roots is one of the most common ancestral myths in the nation, particularly in Warren’s home state of Oklahoma. (It’s even more prevalent than descendants of immigrants suggesting that almost everyone’s name was changed as they passed through Ellis Island.)

Warren could give credence to her claim by undergoing DNA testing, as her former opponent Scott Brown not so helpfully suggested on Monday. “Harvard can release the records, she can authorize the release of those records, or she can take a DNA test,” said Brown, who’s endorsed Trump. “It’s a reverse form of racism, quite frankly.”

But such tests aren’t definitive, and as Brown notes, there’s another factor at play. Being mistaken about her heritage is one thing, but did the blonde-haired, blue-eyed senator exploit affirmative-action programs (which conservatives aren’t fans of in general) in order to advance her career? While both Harvard and the University of Pennsylvania pointed to Warren as proof that they were diversifying their faculty, evidence that Warren herself touted her minority status for professional gain has yet to emerge.

Despite Brown’s often-repeated claim during the campaign that Warren “checked the box claiming she was Native American,” documents obtained by the press show Warren did not claim to be a minority when applying for undergraduate admission to the University of Houston or to Rutgers University’s law school. According to the Washington Post, in papers related to her employment in the mid-’80s at the University of Texas, where Warren did groundbreaking research on bankruptcy, she describes herself as “white.”

However, between 1986 and 1995 she was listed as a minority (but not specifically a Native American) in the Association of American Law Schools Directory of Faculty. Warren explained in 2012, “people for whom Native American is part of their heritage and part of their hearts. There aren’t a lot of people like me in law teaching. And so I just thought I might find some others.” She noted that never actually happened.

So the big question is whether Warren’s claimed minority status made her more attractive to the University of Pennsylvania and Harvard, where she taught on and off from the late ’80s up to her run for the Senate. That hasn’t been definitively ruled out, but several people involved in Warren’s hiring have said her heritage didn’t come up while they were considering her. “I can state categorically that the subject of her Native American ancestry never once was mentioned,” said Charles Fried, who worked in the Reagan administration and served as the head of the Harvard committee that considered Warren.

The Atlantic highlights another big piece of evidence supporting Warren’s version of events: While Harvard was facing criticism for its lack of faculty diversity at the time, the Harvard Crimson article announcing Warren’s hiring in 1995 does not note that she was (possibly) the first Native American on the law school’s faculty.

During the years Warren was at Harvard and the University of Pennsylvania, both schools said they had a Native American woman on staff in federal affirmative-action reports, apparently referring to Warren, though she did not meet that criteria. However, Warren insists she only learned this when it was reported during her Senate campaign, and did not inform the schools of her background during the hiring process. “There was no, there is no reporting for this,” she told the Boston Globe in 2012. “It came up in lunch conversation once with faculty, after the fact.”

Why the Ivy League universities were providing false information to the federal government and describing Warren as a “woman of color” has never been resolved, but that doesn’t necessarily implicate the senator. After years of controversy, the most concrete evidence that Warren benefited from claiming to be Native American is her contribution of several recipes to a 1984 Native American cookbook called Pow Wow Chow. Is that proof that “her whole life was based on a fraud,” as Trump put it? Okay, maybe — if anyone knows culinary chicanery, it’s the man behind Trump Steaks.