Just so we all understand, Shem was the son of Noah. After the flood, the line of Shem stayed spread through the Middle East. Abram (later named Abraham with the insertion of the significant letter “h” in his name denoting the weight of his covenant with Almighty God) fathered both the Jews, the Arabs, and other nomadic tribes of that region. SO, the euphemism “antisemitic” by its origin would mean someone who hates Arabs and Jews. Ironic, is it not?
Note I said Hebrews and not Jews. Technically Judaism is a religion just like Islam is a religion. So it's not antisemitic to degrade a Anglo Jew's religion or a Black Muslim's religion, but it is antisemetic to degrade a Hebrew's race even if she's atheist, or an Arab's race even if he's Cristian.