Do you know which two groups are astoundingly similar? TERFs and Holocaust deniers.
And not just because they're overwhelmingly funded by evangelical Christian groups from the southern United States.
Holocaust denial doesn't match actual history. Gender essentialism doesn't match actual science. In both cases, all the actual evidence points towards the opposite.
1. reexamine the validity of your claim
2. dispute the validity of the source
The latter becomes much harder to do reasonably when literally every single reliable source suggests that your claim is wrong.
But literally all reliable evidence says that everything Holocaust deniers and TERFs say is flat wrong. That's a big problem for them.
TERFs believe that there is a conspiracy - by a "transgender agenda" - to rewrite science to legitmise transgender identity.
"Come on, just think about how difficult it would be to gas and cremate six million Jews. That can't REALLY have happened, can it?"
"Come on, a person born with a penis is male. That's what you've been taught all your life."