Like women more generally, many trans women are feminists. Feminism and transgender activism are not in any way incompatible or mutually exclusive. A… - Julia Serano

Claims that trans women are not women often rely on essentialist (and therefore incorrect) assumptions about biology. For instance, people might argue that trans women are not “genetically female,” despite the fact that we cannot readily ascertain anybody’s sex chromosomes. Indeed, most people have never even had their sex chromosomes examined, and those that do are sometimes surprised by the results. Other common appeals to biology center on reproduction — e.g., stating that trans women have not experienced menstruation, or cannot become pregnant. This ignores the fact that some cisgender women never menstruate and/or are unable to become pregnant. Claims about genitals are similarly problematic: Women’s genitals vary greatly, and as with chromosomes and reproductive capabilities, we cannot readily see other people’s genitals in everyday encounters. If you and I were to meet, should I refuse to recognize or refer to you as a woman unless you show me your genitals? And frankly, what could possibly be more sexist than reducing a woman to what’s between her legs? Isn’t that precisely what sexist men have been doing to women for centuries on end?

Women who insist that trans women are not women often object to being called “cis women” under the false assumption that it somehow undermines their femaleness — this is not at all the purpose of this language. The sole purpose of cis terminology is to name the unmarked majority (similar to how one might refer to white women, or heterosexual women, or able-bodied women, etc.). In other words, referring to someone as “cisgender” simply means that they have not had a transgender experience.

Many cissexual people seem to have a hard time accepting the idea that they too have a subconscious sex — a deep-rooted understanding of what sex their bodies should be. I suppose that when a person feels right in the sex they were born into, they are never forced to locate or question their subconscious sex, to differentiate it from their physical sex. In other words, their subconscious sex exists, but it is hidden from their view. They have a blind spot. (5 - Blind Spots: On Subconscious Sex and Gender Entitlement)