Digressing a bit, though not disagreeing at all:
Fascinating, from a linguistic PoV. In older (racist) usage I've come across "white" being used to mean "morally good", as in "that's mighty white of you." I've seen lots and lots of online discussion on privilege in which there's much angsting on what group is considered "white" now or in the past, and though it hasn't quite been used as shorthand, it's clear that in those discussions "white" means "part of the privileged group, possssing power by virtue of birth."
To my remembrance, this is the first time I've seen "white" as shorthand for "safe from persecution". I instantly understood what you meant, and apparently so did the other 44 commenters (so far), which means it's a very reasonable use in current circumstances. I just think it's fascinating as a marker of change in language and in our understanding of our society.
The meanings are all related. "White" means, in the United States, "part of the majority culture". If you're not white, you're reliant on the legal system to protect your rights as a minority. If you're white, it just happens -- your rights aren't in question in the first place.
"White privilege" is simply the "privilege" of being treated with a baseline of respect and decency. It's NOT, actually, a level of respect ABOVE what people ought to be able to expect -- rather, it's the "privilege" of being treated the way that people ought to be treated in general. It means the "privilege" of NOT being subject to persecution.
I agree that they're related, but I don't think they're identical, and I do think it's interesting watching them drift. I agree entirely with your definition of "white privilege" (and "male privilege", "het privilege", etc). But privilege covers a myriad of things - there's a reason it's "unpacking the invisible knapsack" and not, say, "unpacking the invisible box", where a box often contains one item but a knapsack can be assumed to have a bunch of stuff in it.
In this case, you used the term "white" in reference to the one aspect of safety from persecution, and it's a good usage because it was vivid and immediately intelligible. But even though it's really just a sharpening of a concept in one particular direction it was new enough to me that I found it interesting. I expect I'll be seeing it used that way more often in future.
Huh, I always thought that was because you can carry a knapsack around without noticing it much, fairly often.
I think if you go back 100–150 years, Jews and Southern European immigrants were not considered “white” in the ethnic sense. I have wondered if, in another century, the (Han) Chinese, Japanese, and Koreans in America will also be reclassified as “white”, or if we’ll just come up with a new term for “WASPs and all the other ethnic groups that are almost as privileged as they are”.
Sufficiently light-skinned Jews have only been considered "white" for about 50-60 years. (Insufficiently light-skinned Jews are still not considered "white.")
Your reminder that Jewish ≠ Ashkenazi is noted and appreciated.
However, note also that Sephardi ≠ 'dark-skinned'. Sephardim preceded Ashkenazim to the US.
Actually, historically, Sephardi Jews were considered white long before Ashkenazi Jews were. All the Jews who were, for instance, part of the rulling class in the Confederate States of America during the American Civil War were Sephardic; at the same time period, the same distinction was true in England, where Jews of Sephardic descent could be part of the upper class, but Ashkenazi Jews couldn't.
Later, WESTERN European Sephardic Jews, from Germany and Austria, could be considered white, but EASTERN Ashkenazic Jews -- Polish, Russian, Litvak, and so forth -- were not considered white, not even by Western Ashkenazic Jews or Sephardic Jews. That didn't change until thethe vast majority of them were killed by Hitler.
Although I also understand xiphias
I'm not sure I'm happy about it... to me using a term that denotes skin color (eg white) to denote any other sort of categorization of people (eg those who are not persecuted) is a dangerous conflation of concepts. I'm not sure I'd go so far as to say the association is racist, or a form of stereotyping, but it seems to lean in that direction.
I am, in fact, white, in as much as that's how I fill out forms asking about ethnicity; I'm not safe from prosecution. I therefore don't want people to presume that I don't need to be protected from prosecution simply because I'm white.
is using the term "white" correctly, and conflating nothing. "White" does not denote skin color, it denotes race -- a legal classification with no actual connection to any genotypical or phenotypical phenomenon. There is no skin-tone so light that someone with an ancestor of color would have been categorized as "white."
Before 1950 or so, the statement, "Jesus wasn't a Jew, he was a White Man" wasn't incoherent. At that time, light-skinned Jews were not white.
Around the time of the '50s, Jews became sufficiently assimilated into mainstream American culture that they became white, after which "Jesus wasn't a Jew, he was a White Man" became an incoherent statement.
Your being white does not mean that you are immune to persecution. It does mean that you are immune to racist persecution. That's what white privilege is.
 You might be persecuted on racial grounds, but racial persecution is only racism when it is backed by institutional power. Apologies in advance if this is a distinction you're already aware of.
In the early 1980s, I went to school in a black high school with white honors students, a largely black administration, and a fairly racially mixed teaching staff of highly varying quality (where quality did not vary on racial lines - I had some very good black teachers and some very bad white ones, and vice versa).
By some standards it was a good school. We regularly sent about 5% - 10% of each class to top colleges like the ivy league and MIT; but everyone who went to the good schools were honors students and all the honors students were white (OK, not all - there was one hispanic* girl in one of my math classes - but she is the only exception I remember).
I was a white honors student but poor and therefore vulnerable. I managed to be weird and freaky enough to scare people away from physically or sexually assaulting me, but at the cost of being a social pariah.
I couldn't tell you how much of the social persecution I suffered was the result of my being poor, or weird, and how much of it was the result of my being white; nor could I tell you how much of it was or was not backed by an administration that looked the other way because it's concern was focused on helping black students - nor whether that would count as 'backed by institutional power'. And finally I'll grant that I only suffered social persecution and not academic discrimination (despite being thrown out of the honors track in history, which is one reason I know so much about how varied the school truly was).
So I can't prove that I've suffered racist persecution... but I do not believe it is trivially obvious that I haven't, just because I'm white.
*there is, I think, some confusion about hispanics being a race; most people treat it that way, but technically it's an ethnicity.
There's every possibility some amount of what you suffered in high school was the result of racial prejudice. It is impossible that you've suffered racist persecution, because we do not live in a society in which racist persecution of white people is possible.
Even if we consider the case arguendo where all of your suffering in high school stemmed from racial prejudice, what you suffered is not racism. Yes, the school you were in was a majority people of color. Then you went home, living in a country with a white majority. Then you graduated and exited this majority-white environment. The fact that there is that exit is a difference between what you went through and what a racist system is. This takes nothing away from the reality of whatever it is you suffered -- it is simply that it is qualitatively different from racism.
But I've got to tell you: I went to a white-majority private school, with a small number of students of color. I, too, was a social pariah for most of my time there, and it is not possible that my being white had anything to do with it.
It wasn't all that long ago that Irish people in America were not considered "white". As in, a restaurant might have a sign saying "White customers only", and the people they wanted kept out were those pesky red-headed Celts.