I'll give it a shot.
Not only are "trans-women" truly women....they're the only women.
The only true women are biologically male who identify as women and only true men are biologically women who identify as men.
(I tried to give a rationale for it, but the more I tried to come up with a rationale, the more it started to sound like something a leftist would actually believe because I started invoking words like "Cisgender" and then realized just leaving that statement as is, is more sufficient and crazy sounding than explaining it)
I'm inclined to think it cannot be done. To be a leftist is to fundamentally reject reality, morality, common sense, decency, even literacy.
If I were to offer, say, the ridiculous claim that gravity is racist, I could without much difficulty find you a redditor who either already believes it or could be convinced in moments to spout it as though it was a fundamental underpinning of existence and also that they knew it all along.