The thing is people class others by race not be detailed examination of genetics, but by cursory examination of things like skin tone.
So you get things like thinking of black or affrican as a race when the continent has more genetic diversity than the rest of the world.
So race as people use it is largely a social construct. Like when the Irish became white.
Is Jewish a race? There certainly are genetic markers that show up in jewish communities. So would the Lemba people be classed as black or jewish?
Or is it that there are too many races for people to keep straight in society?
The fact that we can trace with pretty darn accurate certainty, in very notable agreement with past morphological, lineages and where the genome comes out in more or less the same groupings as the older anthropologists did, is more telling for me to the validity of the biological weight of race than its social one. But as you said, "race" as people use it is often in a colloqual way, but that doesn't make the biological reality of the observed differences and groups go away. So, ultimately, like I've said repeatedly; it tends to boil down to a philosophical argument about 'what' to call it (i.e a semantical argument).
I do not agree that "jewish" is a race. I believe, while other usages exist, ashkenazi jewish chiefly and predominately denotes a specific genetic cluster of a people still very much identifiable as such through dna markers, where they have less distance inbetween each other than with other non-ashkenazi europeans/western people, in particular this is evident via their y-chromosome lineage. With regards to the Lemba people in Africa, it's because of our understanding of racial differences (or whatever term you wish to use in its stead) that we could verify some of the historical claims they themselves make about their jewish heritage. If none of the above groups had been definable, at all, by their genetic breed-group heritage (see, didn't use "race"), then it would've been impossible to verify by means of tracing markers since these would mean absolutely zilch as "jewish", according to some, has nothing to do with genetic groupings. But, as it is, they are at least to a notable degree definable as such, in a
biological reality (by whatever term you fancy). Interestingly it seems it would've been mostly jewish males interbreeding with african population there, as opposed to the women, and this would explain the high frequency of the paternal
CMH found while a lack of a maternal equivalent.