As a liberal, I would agree that there is some truth to the idea that if Warren were a Republican, that left-leaning politicians would tear into her more about the Native American thing. She would probably be branded with one of the label-du-jours, “cultural appropriation” or some such.
It’s why being a leftie, I try not to fall into lockstep with every bandwagon the left’s politicians are currently saying. When you’ve been around as long as I have, you start to notice that the left and right flip-flop on some of the issues. For example, years ago it was the left promoting tariffs and the right who were opposed to them. I wish the two sides, and the voters, would do a better job of prioritizing their fights.