This is historically totally incorrect. Not a few Jewish arrivals to America were after their aborted attempt at communist revolutions in Germany, first in 1848, and again in the early 1920s with the backlash against the Sparakusbund, a job that Hitler completed in the early 1930s.
How so many Jewish people became leftists in the first place is a very long history. For now, I'll just say that it was planned, and not for their benefit.
Eastern European Jewish communism grew from Karl Marxs' time onward. (from about 1818 onward) He was a popular philosopher and revolutionary amoung Jews. I don't know how you say "it was planned, and not for their benefit". I'd like to hear that theory. Early Jewish arrivals in North America were already commies when they got here.
Sorry you missed the historical time frame. My statement is not “totally incorrect.” That small number of Jews that you refer to that arrived in the USA following the European Revolution of the late 1840s could join none other than a conservative party. In contrast, the great number of American Jews trace thir heritage to East European arrivals in 1890-1910. By then the radical political elements influenced by European political thought were forming in America, and they soon had a leader in Eurgene Debs. The number of Jews who arrived in the USA in the WWI-WWII period don’t amount to much as the leadership of American Jewry — on the left, right and center — was by then pretty well fixed.