To a jew in 1880 any Western European country might at any moment expel jews on religious grounds, while the United States enshrined religious tolerance in its Constitution, extending it to jews from the first (jews could always vote), and even to the many outrageous cults which flourished here and for which the US was justly famous.
So of course when things got hot they swarmed over.
It is 1000X more important that governments be anti-immigrant than it is they be anti-Israel.
Not that the latter is even on offer. I mean NJP gave it the old podcast try, but...