The point you bring up is an example of "fallacy of equivocation".
Yes, words are polysemic. In this case, 'anti-semetic' is seen as "anti-jewish". That's one sense of 'anti-semetic'. You can also add another sense of that word: "against speakers of Semetic language or people". This sense is not used when people use 'anti-semetic'.
In Europe, there has been centuries of discussion about jews: it was called "the Jewish question". Anyway, this anti-semitism started as a product of religious rivalry (which religion is True? Christianity or Judaism). Then extra features were added, etc.
Yes, words are polysemic. In this case, 'anti-semetic' is seen as "anti-jewish". That's one sense of 'anti-semetic'. You can also add another sense of that word: "against speakers of Semetic language or people". This sense is not used when people use 'anti-semetic'.
In Europe, there has been centuries of discussion about jews: it was called "the Jewish question". Anyway, this anti-semitism started as a product of religious rivalry (which religion is True? Christianity or Judaism). Then extra features were added, etc.