The point is that this puerto-rican, irish or italian stuff can be carried too far, and with deadly consequences. Assimilation into American society is the best route for all. But no, those who trumpet the "old country" for whatever motives are often with us and Sowell's point here is that they are destructive of something that is good in the human spirit.
That's what gets me. Obviously, ALL immigrants left the country of their birth to come to America because there was something wrong with their native country. If there wasn't, they wouldn't have left in the first place. Why would anyone, who leaves an inferior situation want to make their new situation the same as the one they left???
They came to America because it is the best nation in all aspects of opportunity, freedom, and standard of living, bar none, on the face of the earth. LEAVE IT THAT WAY AND CONFORM!!!! ya winey pukes.