Today, the same fallacy is also used to ban trans people from public bathrooms. The trope starts as Cis Man in Disguise for the Motive of Cheating to win a women's athletic gold medal, and it mutates to Cis Man in Disguise for the Motive of Preying on unsuspecting women in a bathroom. This trope never makes literal sense because, if you put yourself in the mindset of a fictional cis male villain, you realize the steps he'd have to carry out for his plan would be elaborate and bizarre and the cost-benefit analysis wouldn't work out in his favor. The trope is only comprehensible as transphobia; it's a cruel joke meant to forcibly out and socially isolate trans, intersex, and queer people.

Why this history is important today

The moral panic over trans people in sports continues not to be about sports. As in the early 20th century, most of the people today who make noise over trans people allegedly spoiling women’s sports aren’t doing anything to appreciate or fund women’s sports nor to support or elevate women athletes. Instead, they say quite a lot about excluding trans people from society broadly. Their moral panic over trans people in sports is primarily about their perception of trans people and what they’d like to do to us. They show it to us all the time.

I always ascribed it to Nazi gender distortions, and figured there was actual history behind it. Having any separation by gender in sports removes the ability to just see who the best is one at a time or to each their own lane. It’s not trial by combat or contact sports after all. And anyone behaving badly should just be kicked out regardless. There are a lot of old echoes of that terrible period in history and the world powers’ desire for supermen. The dysmorphia is everywhere these days because they didn’t execute or keep under arrest the Nazi scientists.