First of all, the reason roughly 70% of Jews voted for Biden (76% for Hillary in 2016) included the fact that most Jews do not care about Israel. The cliche is all Jews are still like the era when The Ten Commandments and Exodus were in theaters and people rooted for Israel in the 1967 war. Now fewer care much.
That time is gone. Few Jews care for Israel and most do not like Natanyahu or Trump. Most Jews are not observant and few are regular attendees of religious services. Reform lowest, then Conservative, then more observant and right wing politically Orthodox and Lubavitchers.
I think it simpler than that. Jews were the excluded class in Hitler’s era. So Jews tend to move towards the party which claims to be more inclusive. And that is the democrat party. Ditto with Chinese, Indians, and most immigrants.