...even when they are in no real political danger? Tells me that they wanted to do it all along. Newsom isn't stupid. He's perfectly capable of understanding what anyone does if they look at the actual evidence - trans girls, on average, do slightly WORSE at sports than cisgender girls. Unfortunately, it SOUNDS true that "men have a biological advantage over women", and most Americans are low-information and not generally interested in going further than those five seconds it took to contemplate that, but a lot of people thinking it doesn't make it true (I don't even know what that's supposed to mean for some sports that have been brought up, either. Like, one team that got contentious was a volleyball team. Erm, don't I too technically have a biological advantage in volleyball because I'm tall?).
And, of course, this is a small fraction of a group that is believed to be roughly 1% of the population. But even WITH that, Newsom is still wrong and capable of understanding that he's wrong. If he's being this loud and proud about it, it's because he wants to be that way.