Last year, I wrote about a federal court opinion in Bonadona v. Louisiana College, addressing whether Jewishness is a "race" for purposes of Title VII litigation. The question rarely comes up, because Title VII also protects against religious discrimination, and so Jews suing on basis of antisemitism typically just use that as their statutory hook. But Bonadona involved a Jewish-born convert to Christianity, who was nonetheless allegedly denied a position at a Christian university on the basis of his "Jewish blood" (yes, that phrase exactly). So he couldn't claim religious discrimination -- he was Christian, just like his would-be employers -- but the reference to "Jewish blood" certainly smacks of an employer who viewed (and disparaged) Jewishness as a race.
The decision last year concluded that Jewishness is, or at least could be, a race for Title VII purposes. But it was actually only a magistrate's recommendation, and a few days ago the district court judge apparently overruled that recommendation (via) and decided that Title VII categorically does not provide protections to Jews as a "race" because Jewishness was not understood to be a race in 1964 (I say apparently only because the court's opinion does not mention or discuss the magistrate's recommendation in any way).
This lack of discussion is disappointing, since the magistrate's opinion raised some issues that I think are worthy of discussion but get no attention in the relatively sparse treatment offered by the district court. The latter's analysis begins and ends with (for what it's worth, uncited) declaration that Jewishness wasn't viewed as a race in 1964, and so consequently the statute could not have been intended to encompass Jews (at least, as a race). This distinguishes the Bonadona case from other precedents which found Jewishness was a race for the purpose of Section 1981 litigation -- Jewishness was seen as a race in the 1860s, but wasn't by the 1960s.
To me, though, this analysis isn't persuasive, and smacks of a sort of vulgar textualism (what in the constitutional context is sometimes called "original expected applications originalism) that is just wrong as a matter of fundamental legal interpretation. The right question -- even from an originalist/textualist vantage -- isn't whether Jews were (by everyone? the majority? themselves?) viewed as a race in 1964 (or 1866). It's whether, under the prevailing understanding of "race" that would have dictated meaning in 1964, Jews are being viewed as a race now (either generally, or in the particular fact pattern at issue).
For example, suppose that in the mid-1970s, a race of human mole people emerged from beneath the earth and sought to integrate into above-ground human society. Though they're biologically human, they have their own distinct customs and practices, and are physiologically distinguished by their dark blue skin. In the United States, they are quickly assimilated into normative American race politics (e.g., White supremacists hate them, some people are nervous about allowing them into their children's public schools, a network of stereotypes about them quickly entrenches itself, and so on). Are they a "race" for Title VII purposes? It'd be weird to answer "no" because in 1964, "moleman" (not yet having been discovered) wasn't recognized as a race. Rather, the question is, given what "race" was understood to have meant in 1964, whether the manner in which the mole people are being treated corresponds to a racial category. If the answer is "yes", then they're a race for purposes of the statute. If not, then they're not.
The reason we have to stretch to a hypothetical about "mole people" is that it's quite hard, under prevailing contemporary understandings of race, to imagine a clear cut example of a new race being "discovered". In reality, while race is not a static concept, social groupings don't move into or out of the category all at once. In the case of Jews, for example, sometimes we've been viewed as a race and other times not, and even within a discrete time period some people have viewed us as a distinct race and others not. White supremacists today still discriminate against Jews on racial, not (just) religious, grounds, even though many other people do not view Jews as racially distinct. That was probably equally true in 1964. It seems very odd to say that discrimination that is both expressly described by the perpetrators and acutely experienced by the victims as occurring on racial grounds is nonetheless not on basis of "race" because ... what, exactly? Jews aren't "really" a race? There isn't a metaphysical or biological reality to race, other than how it's performed -- the act of treating a group as racially distinct is all there is to race-ing a group.
Consequently, I'd suggest that, at minimum Jews are a race for Title VII purposes in cases where the discriminatory treatment they experience is racialized. The markers of racialized treatment -- which I think had purchase in 1964 -- are things like viewing ones personal character or human value as dictated by one's biological ancestry, assuming sweeping similarities across a wide range of character traits based on perceived physiological or genetic similarity, viewing the group as one which has the potential to degrade or "pollute" the gene pool, perceiving membership in the group as per se (or at least highly suggestive) evidence for all individual members that they are congenitally incapable of integrating with others not-like-it, and so on. Admittedly this may not be amenable to being nailed down with precision-- but that fuzziness is probably why Title VII doesn't attempt a definition of "race" (if it were as simple as "the groups that were generally classified as races in 1964", then the statute could have easily just given that list). To a large extent, when it comes to whether a particular group is being viewed as a race, "we know it when we see it".
Does the above rule -- where one is a race when one's discriminatory treatment is racialized -- cover all cases of antisemitism? Not necessarily. Someone who refuses to hire a Jew because "they don't worship the same God I do" is engaging in religious discrimination, but that sort of statement does not on its own evince a view of Jews as a distinct racial group. One can imagine a range of cases that get grayer and grayer as you approach the middle, but refusing to hire someone because of their "Jewish blood" seems to sit pretty comfortable on the far side of the spectrum.
And this, I think, represents a more faithful application of the original understanding of the word "race" in Title VII than the casual inquiry given by the District Court. It is unlikely that the drafters of the Civil Rights Act thought of themselves as protecting certain ahistorical and immutable categories of "races" that existed from the depths of antiquity and would persevere endlessly into the future. By 1964, when we had started abandoning the view of race as a biological reality and instead treated as a sociological category, a "race" for Title VII purposes is a group that is treated as a race in cases covered by the statute.