I would assume those would the Jews who are now back in the land!Are they Jews by their ethnicity, their 'race', or their 'birth'?
According to Webster's, 'ethnicity' means "the fact or state of belonging to a social group that has a common national or cultural tradition."
'Race' means "each of the major divisions of humankind, having distinct physical characteristics."
By 'birth', I assume you mean by a genealogical relationship to Jacob.
I admit that I struggle with the WLC Q 191, where it says we should pray that the Jews are called. I have no problem praying that all sorts of people are called, but who were these 'Jews' to which the Reformers referred? Who are the 'Jews' to which modern day Dispensationalists refer? I heard a prominent Calvary Chapel pastor once say that we don't know who they are. If that's the case, then maybe they already have been called and we don't know it because we don't know who they are.