I think it has to do more with the economic standard of the Jews and Gunieas that were coming in. It was mostly Italian peasants from small villages in the back ass of nowhere that came to New York. If it’s economical, it takes a generation or 2 to stamp out the discrimination, which were the case for these folks.
The Irish potato farmers were spit on and abused as well.
I think the Irish were discriminated for behavioral reasons (alcoholism and backwards culture apparently) and how they hated Anglos (many early Americans were Anglo?), but there must have been a sliver of racial issues with dark ass Italians and the Semitic looking Jews. It couldn't just be cultural with them.