America's lack of discrimination based on race is the exception, not the norm. Most cultures have a tradition of supremacy over all others, this mindset is in our DNA.

Judaism is no different. When the escaped slaves from Egypt arrived in the Canaanite lands of Israel and Judah, the elites there were fascinated by their god and wanted him for themselves. So they mixed their stories with their own pagan and Canaanite traditions, and wrote phony books that would eventually be combined into the form we have them today: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy. One of their corruptions was making this new god and all his blessings for themselves only, justifying evil against other peoples and only requiring regard for other Jews. During the Babylonian exile things got even worse, with Ezra who especially hated gentiles, and the beginning of the Talmud which has some absolutely disgusting teachings.

This isn't a problem with Jews specifically. The Romans did the same thing to Christianity, they've simply had much less time to do it. Still, they managed to make some radical changes in just a few centuries, including somewhat being able to inject the idea that Romans are better than everybody else. To this day Rome is considered sacred to Catholics, and the church also has a long history of anti-semitism.