It’s those magic words “I am an XYZ…” that prevent any eyes from rolling. Those words provide an untouchability and radioactivity around the speaker that we have yet to integrate into modern discourse. As OP said, the good faith nature of argument is turned on it’s head by identity, not merit, based logic.

I disagree with cynicism of the OP however. Many people are just tied up in a movement, without a conniving pathos driving their support. If you look at the historical context identity arguments arrive from, it is very much reactionary to past oppression. And society tolerates reactionary swings for only so long before seeking homeostasis. It is possible (likely, even) that the junior professor behind the vitriol is doubling down due to self preservation. However, I don’t think her supporters are as interested in her self interest so much as they are interested in supporting the movement as a whole. She’s more or less an ideological soldier; yes she may have violated her enemies in atrocious ways, but she is fighting for home team, and thusly retains support regardless of abuse of basic logic.

Hopefully we out grow this phase soon because the ignorance inherent in that support does seem culturally toxic.