the vast majority of American support for Israel comes from the Christian Evangelical right, not from Jewish americans. I've never met a single Jewish person who actually supported isreal that was aware there was a genocide taking place. most of them have just been grossly misinformed about who lived there
One of my best friends is Jewish, and while in general I think he has a fine sense of justice, he also has relatives in Israel and is susceptible to jingoistic calls to “stand with Israel”.