If Liberals don't believe in biological gender, then why exactly do they march for "women's rights"?

That is a good question. And if we don't believe in gender than how could Hillary have become the first female President?

You are so pathetic, mental illness is so endemic in this country

Because of the manner in which women have been treated over the centuries.

And not all liberals "don't believe in" biological gender. Learn not to generalize.

They are actually marching for non-men rights.

They aren't mutually exclusive. A man who sees herself as a woman will still be eligible for women's rights (i.e. not being discriminated against for identifying as a woman).

We believe in biological gender. We just don't believe that it is as rigid as people like you want it to be. Transgenders and gays have existed since the world began, which you would know if your home schooling had ever covered anthropology. Before science was able to alter physical characteristics, their societies accepted them. Margaret Mead talks about the tribes in the South Pacific and how they accepted men who acted in female roles. The Native Americans considered them magical beings.

You are free to continue to refuse to accept reality and criticize those who are "victims" of it all you want. It will never go away.

They don't understand that gender is grammatical; sex is biological.

I got asked my "gender identity!" That isn't proper English.

I'm guessing you're not married / have no girlfriends... too funny......