The main argument against self identification is that trans people are a danger, but this is deeply untrue
The advocates of the various “bathroom bills” have adopted the stance that allowing transgender people to use the bathroom they identify with would lead to more sexual assaults. Proponents of prohibitive restroom policies argue that trans women pose a threat to cis women and children in a shared bathroom environment. They assert trans women are more dangerous and cis men could assume the guise of a trans woman to gain access to public bathrooms and commit sexual crimes.
In places where transgenders are already allowed to use the restroom of the gender they self-identify with, there has not been a rise in sexual assaults. In Massachusetts, for example, there was no difference in sexual assault rates and no difference between sexual assault figures between cities that allowed trans citizens to self-identify and those that didn’t. A similar study undertaken by the UCLA School of Law produced similar findings. In fact, there have been no reported cases (as of June 2017) of a trans woman sexually assaulting a cis woman in a public restroom. Secondly, sexual assault still remains illegal. Those that commit it are still carrying out a crime. If a predator wishes to gain access to the female restroom, they will do it regardless of the laws. Abusers will do awful things regardless of the law, as they have since the beginning of civilization. Whether or not trans people can use the bathroom of their identified gender has no bearing on this.
Allowing men who identify as women into women’s bathrooms will lead to voyeuristic offences, sexual assaults, and rapes. If we let transgendered people choose to use the restroom they feel most comfortable with, we are essentially inviting males, born with male genitalia to use a female restroom. It provides an opportunity for them to commit sexual assault or harassment. Other men may also claim to be trans to gain access to female restrooms. Former Arkansas governor Mike Huckabee, when he spoke on the issue of trans people using the bathroom that matches their gender identity, said, “I wish that someone told me that when I was in high school that I could have felt like a woman when it came time to take showers in PE,” adding, “I’m pretty sure that I would have found my feminine side and said, ‘Coach, I think I’d rather shower with the girls today’”.
P1. Trans women are no different to cis women. P2. They do not commit more sexual assaults. C1. They should be allowed to use the same bathroom.
There is a reason why we separate bathrooms. We need to give women a safe space. Men in that bathroom could pose a risk to their safety.