“Jews earn like Episcopalians and vote like Puerto Ricans” is a paraphrase of what Milton Himmelfarb (1918-2006) wrote in the June 1973 Commentary magazine, in the article “The Jewish Vote (Again).” Himmelfarb meant that Jews earn like the rich establishment (Episcopalians), but vote like poor, recent immigrants (Puerto Ricans).
 
Milton Himmelfarb’s observation about the Jewish vote has been repeated frequently in books, magazines and newspapers.
 
       
Google Books
Commentary
Volume 55
June 1973
Pg. 81:
The Jewish Vote (Again) by Milton Himmelfarb
(...)
Although American Jews had come economically to resemble the Episcopalians, the most prosperous of all white groups, their voting behavior continued to be most like the voting behavior of one of the least prosperous of all groups, the Puerto Ricans.
 
6 April 1976, New York (NY) Times, “The Jewish Voter In New York’s Poll” by R. W. Apple Jr., pg. 23:
As Milton Himmelfarb of the American Jewish Committee likes to point out, the conservatism of poorer Jews as against the views of the richer ones runs counter to the usual American experience. More prosperous Jews, he has written, have the socio-economiuc status of Episcopalians, but tend to vote like Puerto Ricans.
 
30 March 1980, Los Angeles (CA) Times, “Carter’s New York Woes” by William Schneider, pt. IV, pg. D1:
“Jews,” author Milton Himmelfarb once said, “have the wealth and status of Episcopalians and vote like Puerto Ricans.”
   
23 November 1984, Los Angeles (CA) Times, “Political Apostacy Is Tempting, but Jews Keep the Faith” by Michael Kinsley, pt. II, pg. D7:
Jews live like WASPs, the saying goes, and vote like Puerto Ricans.
   
6 June 2000, New York (NY) Post, “Clinton’s Israeli Minefield” by John Podhoretz, pg. 33:
In the 1970s, the political scientist Milton Himmelfarb quipped that Jews earn like Episcopalians and vote like Puerto Ricans, and the same is true today.
 
New York (NY) Sun
Milton Himmelfarb, 87, Witty Essayist on Jewish Themes
By STEPHEN MILLER, Staff Reporter of the Sun | January 11, 2006
Milton Himmelfarb, who died January 4 at 87, was a former editor of the American Jewish Year Book and an erudite and witty writer on Judaism, politics, and modernity, whose essays often appeared in Commentary.

He was perhaps best known and certainly most often cited for his observation that American Jews “earn like Episcopalians, but vote like Puerto Ricans.” It was a nice way of formulating the paradox that Jews are perhaps the only significant ethnic group in America not to have become more conservative in its voting patterns as it climbed the economic ladder.
 
New York (NY) Times
Milton Himmelfarb, Wry Essayist, 87, Dies
By JOSEPH BERGER
Published: January 15, 2006
Milton Himmelfarb, a leading essayist for Commentary and other publications who was known for his well wrought and witty observations on Jewish affairs, died on Jan. 4 at Memorial Sloan-Kettering Cancer Center in Manhattan. He was 87 and lived in White Plains.
(...)
And in his most famous phrase, one that political scientists and reporters admired for its concise ability to express why Jews remain liberal even as they become affluent, he said that Jews “earn like Episcopalians and vote like Puerto Ricans.”