If you cannot defend a position without changing the root topic then maybe what you’re defending isn’t as cut and dry as you think.
I was showing you the fault in your logical argument by applying your same formulation to a different example. It's not changing the root topic, it's one of the most common pedagogical techniques.
Racism and genderism is completely different. You cannot change your race but through ELECTIVE surgery or through simply changing your identity you can change your gender.
You're confused. Racism and transphobia are two forms of bigotry. Just because they're not exactly the same doesn't mean they're completely different, just like racism and sexism aren't exactly the same. It depends on the context you're arguing within. And there are many examples of racism being deployed through elective contexts, such as denial of naming rights, religion, hairstyles, language, etc. Racism isn't as simple as you make it out to be, there is a constellation of factors and contexts through which it can manifest.
A transgender person being able to match their government ID with their gender identity is not an example of them
becoming transgender, any more than people referring to you as a female would mean you're
becoming a woman. Transgenderism is just when your self-perceived gender identity doesn't match the gender you were assigned at birth. Sex-reassignment surgery and changing government documentation is just about having bodily and social alignment and acceptance of your innate identity. Just because a black person is passing or has vitiligo doesn't mean they're no longer black. And if the next time you renew your license at the DMV and they put an F next to your Sex it doesn't mean you're a woman until you rectify that mistake, even with the discomfort you'd feel with having that be your state-determined gender designation.
It’s okay to agree with science and say that trans women have an unfair advantage against women thereby oppressing cis women in the process.
Depends on what arena you're talking about when you reference an unfair advantage, but this is not the bullying that TNC is talking about. If the extent of anti-Trans activism was doing academic studies on the differences between Trans women and Cis women, we would not be in the place we are right now.
I will always defer to defending cis women than trans women, especially when people who defend trans women won’t even admit that they’d date one there by conceding the point the there is a material difference between the two.
There is no definitive opinion held by cis women on this issue, so you're going to have to form your own opinion on this.
And not being sexually interested in trans women is completely irrelevant to this topic. I don't want to date a woman taller that 6'4" but that doesn't mean I think tall women deserve less rights, opportunities or humanity that shorter women. No one is claiming there is no material difference between trans women and cis women, they're saying trans women belong as a subcategory of woman.
I support trans people being able to identify who they are and to transition as freely as they like but I don’t support oppressing CIS women just so trans women can feel more feminine
I don't know what oppression of CIS women you're talking about but the bullying TNC is mentioning is the passing of laws specifically targeting trans people for discrimination.