Commonly known as Trans Exclusionary Radical Feminists or Gender Criticals.
TERFs oppose the self-definition of trans people and gender as a social construct. They root their feminism in the false dichotomy of the gender binary (sex).
TERFs dogmatic focus on gender essentialism simultaneously excludes and vilifies trans people in their core beliefs – they see trans women as men perpetuating the male patriarchy, while they see trans men as women that are victims of the patriarchy who have no agency in their choices because they’ve been brainwashed to hate their bodies.
TERFs have essenialized genitals as the determining factor for what they define as gender (sex), penis = man, and vagina = woman, and nothing can change their point of view on that. And quite often you’ll find that intersex people are left out of the conversation entirely.
TERFs focus their activism & actions on attacking trans rights specifically, and that is in part due to a huge amount of propaganda that began to spread in the 1970’s and 1980’s.
One of the foundational texts for TERFs beliefs, “The Transsexual Empire” written by Janice Raymond in 1989, specifically states: “the problem with transsexualism would be best served by mandating it out of existence.”
To be clear TERFs literally support the erasure and eradication of transgender people, because punching down at other oppressed groups gives them a sense and feeling of agency that they would not otherwise have.
For a more in depth explanation on TERFs and their ideology/ beliefs are broken down in a great video by Jessie Gender: ‘What Are TERFs? – How “Gender Critical” TERFs Harm Transgender Folks’