What is the secular basis of Judaism? Practical need; self-interest. What is the worldly religion of the Jew? Huckstering. What is his worldly god? Money. Very well, then! Emancipation from huckstering and money—consequently from practical, real Judaism—would be the self-emancipation of our time. […]It’s always been okay for the left to hate Jews. The left invented the modern form of it.
… Money is the jealous god of Israel, in face of which no other god may exist. Money degrades all the gods of man and turns them into commodities. Money is the universal self-established value of all things. It has, therefore, robbed the whole world—both the world of men and nature—of its specific value. Money is the estranged essence of man’s work and man’s existence, and this alien essence dominates him, and he worships it.
The god of the Jews has become secularized and has become the god of the world. The bill of exchange is the real god of the Jew. His god is only an illusory bill of exchange. …
— Karl Marx, “On ‘The Jewish Question’”
The Karl Marx reference is correct, of course—and shows just how weird this topic really is.
Leftists have always been “cafeteria Marxists”—picking up those pieces they like, ignoring pieces they don’t—and then updating them with more modern templates like Gramsci and Marcuse and the deconstruction folks.
The key point imho is that leftist Jews always considered themselves part of the oppressed masses—no matter how much wealth and power they had in the real world.