Abraham, Isaac, and Jacob descend from Shem, one of the three sons of Noah. They are, therefore, S(h)emites. Hence the term, 'anti-Semite.'

If the _Ashkenazi_ Jews are descended not from Shem, but from Japheth...then that rather confuses the narrative a bit about being 'God's Chosen' who have a 'divine right' to the land. A rather important talking point these days...