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”.
There are two wrong sides here... so it can be difficult to predict what anyone will lean further away from. Beware of assuming that means they are leaning toward the other side though.
It's funny how people always cite Einstein on this letter but not Hannah Arendt. Given the subject matter I'd think of her as a way more relevant expert. Probably more about overall pop culture fame than sexism but interesting nonetheless.