I'm pretty sure that when xiphias
"I'm Jewish. Right now, Jews are mostly considered more or less white. But that could change. And the second it does, people will start saying things like, 'Well, sure, they COULD build a synagogue there, but wouldn't that just be asking for trouble?'"
And in particular when he says, "But that could change," he's not anticipating the lose of white privilege, but an increase in anti-semitism and / or the importance of Christian privilege. And the fact that light-skinned Jews became white somewhere between fifty and a hundred years ago is largely incidental to that.
In which case he *is* conflating things.
It's OK with me if society uses the terms "white privilege" or "white" along purely racial lines; what's not OK is when it starts treating all privilege as white privilege, and using "white" as a short hand either for "part of the privileged group, possessing power by virtue of birth" or for "free from [all] persecution", although I find the latter much more disturbing than the former.
I also think that some term for "free from all persecution" would be useful. I just don't think "white" is a good term to use, because if it were, it would be confused with the purely racial use of the term, which could lead to all sorts of trouble, not just for people in my situation.
What happened to me in high school is not at all straightforward. To your way of thinking, the experience wasn't universal enough to count as a loss of racial privilege (technically, in some ways, it would have been a lack of black privilege, not a lack of white privilege, since this was an environment and power structure that favored blacks; but I could hardly blame my fellow students for protesting their very real, and concurrent, lack of white privilege in society at large, not even when they took it out on me).
It's not clear to me how universal something has to be to count. As a teenager I lived in an environment, at least the majority of the time, where the dynamics of white privilege were not the same as in the rest of American society; but you're right, in pointing out, that - despite my inability to escape it - it was encapsulated in a society where white privilege was the standard. And that mattered. The question, to me, is how much it mattered.