it seems to me that it's these tribes that are being racist in refusing to accept that a phenotypically white person may have some native american ancestry - they are refusing to accept her as one of their own because of her skin colour, and that she be called out and denounced.
more broadly speaking, this is something that should be spoken about with greater transparency. there is widespread misunderstanding all around about this that needs to be properly held up to rigorous scientific scrutiny.
despite what some tribal leaders may imagine is the case, the fact of the matter is that indigenous is not a closed identity, and indigenous groups have taken in genetic variation from all over the world, particularly western europe and western africa. indigenous groups in north america have changed so much through the introduction of foreign genetic material that their ancestors would not recognize or understand them at all. there are some indigenous tribes that report over 80% r1* markers, which is the indo-european male marker - these groups are dominantly european in their ethnic background, yet they have no problem claiming indigenous identity, despite having minimal indigenous ancestry. and, these aren't posh senators from massachusetts, they're people with influence in their own communities.
in 2018, essentially nobody east of the rockies is going to test as more than 30% indigenous. that's the cold, hard fact of it.
is there a concept of metis in the united states? in canada, elizabeth warren would haven't to identify as a specific tribe to gain indigenous rights, she could identify as what we used to call a "half-breed" and today call "metis". but, see, this is a consequence of the fact that canada doesn't have a history of one-drop definitions in terms of racial identity. in latin america, you have an entire vocabulary of different categorizations; in the united states you're either white or not. and, maybe that's really the problem.
depending on the test, i'm likely to test positive for native ancestry, jewish ancestry, african ancestry and asian ancestry - despite being widely mistaken for white. i'm only, like, 30% white. and, i don't know how to identify, besides rejecting the premise. so, i have a little empathy around this.
people condemning her for this should really take a step back and reflect on what they're doing and whether they can really justify it or not - because the actual empirical reality is that a random sample of phenotypically indigenous people is not going to be very indigenous in the genotype, in the first place. you're really, legitimately just criticizing her for what she looks like - and that shouldn't be normalized or accepted.
https://www.nytimes.com/2018/12/06/us/politics/elizabeth-warren-dna-test-2020.html?module=inline