Sen. Elizabeth Warren’s decision to release a DNA test verifying a claim to (very distant) Native American heritage was always a strategy of necessity rather than choice. This claim dogged Warren in her first Senate campaign in 2012, and regardless of the appropriateness of President Trump’s “Pocahontas” attacks on her, it very much threatens to be a liability if the Massachusetts Democrat runs for president in 2020.

Now the gambit seems to have backfired with some prominent Native Americans — most notably the Cherokee Nation. And that group’s response is particularly important when you consider this: Six years ago, it gave Warren a pass.

The Cherokee Nation’s secretary of state, Chuck Hoskin Jr., released a blistering statement Monday in response to the test showing Warren was between 1/64th and 1/1,024th Native American:

“A DNA test is useless to determine tribal citizenship. Current DNA tests do not even distinguish whether a person’s ancestors were indigenous to North or South America. Sovereign tribal nations set their own legal requirements for citizenship, and while DNA tests can be used to determine lineage, such as paternity to an individual, it is not evidence for tribal affiliation. Using a DNA test to lay claim to any connection to the Cherokee Nation or any tribal nation, even vaguely, is inappropriate and wrong. It makes a mockery out of DNA tests and its legitimate uses while also dishonoring legitimate tribal governments and their citizens, whose ancestors are well documented and whose heritage is proven. Senator Warren is undermining tribal interests with her continued claims of tribal heritage.

Trump played up the statement in a tweet Tuesday morning:

However you feel about Trump’s rhetoric or Warren’s claims, the rebuke is a significant political moment. This is the very nation to which Warren claims a connection saying that she is “undermining tribal interests with her continued claims of tribal heritage.” They’re effectively saying her claims and efforts to prove her heritage are no longer helpful and even harmful. Individual Native Americans have denounced Warren before; now the Cherokee Nation has taken a pretty firm stand against her, thanks to the DNA test.

And just as important as the tone of the statement is its trajectory — something of a reversal of course for the Nation, which back in 2012 declined to criticize Warren and even defended her.

In an interview at the time, Cherokee Nation Principal Chief Bill John Baker said of the controversy that Warren “never claimed to be a member of the Cherokee Nation” and only claimed native ancestors. “I wish every congressman and senator in the U.S. had a kinship or felt a kinship to the Cherokee Nation,” Baker said. Baker was also often cited by Warren’s supporters, given his own limited native Cherokee ancestry. He is 1/32nd Cherokee.

The Cherokee Nation otherwise didn’t weigh in on Warren’s claim.

The nation did rebuke one candidate in that 2012 race, but it was then-Sen. Scott Brown (R-Mass.) rather than Warren. After Brown staffers and supporters were caught on camera making war whoop chants and doing the tomahawk chop, Baker took issue with Brown’s lackluster response.

“The Cherokee Nation is disappointed in and denounces the disrespectful actions of staffers and supporters of Massachusetts Sen. Scott Brown,” Baker said. “The use of stereotypical ‘war whoop chants’ and ‘tomahawk chops’ are offensive and downright racist. It is those types of actions that perpetuate negative stereotypes and continue to minimize and degrade all native peoples.”

“. . . I call upon Sen. Brown to apologize for the offensive actions of his staff and their uneducated, unenlightened and racist portrayal of native peoples.”

It’s one thing for Warren to lend some credence and proof to her ancestry claim; it’s another for that claim to be judged sufficient for Warren to use it in a professional setting. The Cherokee Nation’s statement and the reactions of other Native Americans suggest they’re unwilling to accept the latter.