Sorry if this seems like needlessly stirring the pot, but I was thinking back the other day to a conversation I had with my sister, an ardent Clinton supporter. And basically what she said (at one point) was that she didn't understand how Bernie supporters could call Hillary the "establishment candidate" because she's a woman. Which just feels to me that she, and the people who thought/think like her, just refused to even try to listen to the progressive wing of the party.
The establishment does not mean that someone is not a part of a marginalized group, it is a judgment of the type of people the politician is representing.
Are they representing the people or the powerful?
It was evident, that while Hillary does stand for some things that benefit the people, she primarily is beholden to the established powers in Washington: Lobbyists, Major Corporations and the Wealthy.
Politicians personal characteristics to not keep them from being a part of the Establishment. It does not matter what marginalized group they are in if they are bought and paid for, they are a part of the establishment.