As a moderator, I don't like these agruments
I doubt that there is really than much tension between the two sets of emigrants.
Many Puerto Ricans, integrated in the system, educated, at least bilingual, some with just English, have begun the upward mobility associated with emigrant groups in general, over time.
Dominicans, more recent arrivals, have supplanted the Puerto Ricans in many of the job slots throughout New York City, and the Puerto Ricans have moved further afield (as was reported in a thread on "bodegas").
The Lower East Side is no longer a Puerto Rican enclave. It now has a large Dominican population. Upper Manhattan, never a Puerto Rican "barrio" has become "Little Santo Domingo". Parts of Queens are known as "Sabana Church" for the large number of people from Sabana Iglesia (near Santiago) that have moved there. Puerto Ricans were never an important segment of either of these areas.
That said, there are many rivalries between emigrant groups, but that does not necessarily mean violence.
If you have something serious, non-inflamatory to add, send me a PM.
HB
Moderator