That Hispanics of Cuban origin are approaching the voting patterns of other Hispanics indicates that the GOP is losing them.
In what way does this poll suggest that their voting patterns are converging? They look pretty different in this poll.
From the poll:
Cuban-Americans in Florida used to be a reliably-Republican voting bloc. Republicans can no longer rely upon the appeal that "Democrats are tools of Fidel Castro".
What are you talking about? Romney has a huge lead among Cubans in that poll, according to the very numbers that you're quoting, while Clinton has a huge lead among non-Cuban Hispanics.
I discuss a change from the past in which most Cuban-Americans, at least in Florida, were reliable voters for Republicans in Presidential elections. Not all Hispanics in Florida are Cuban-Americans, and non-Cuban were never as amenable to GOP appeals that "Democrats are buddies of Fidel Castro". If one is a Mexican-American, is "Fidel Castro" as visceral a set of syllables as they were to someone who had fled Fidel Castro?
From the poll:
This is very different from:
I think that we are seeing Republicans show that they have become incompetent at making successful and relevant appeals to Hispanics of any kind, and the execrable performance of Republicans among Cuban-Americans shows that such a failure comes from a difference in culture. To be sure, "Cuban Hispanics" are no longer as lily-white as they were in the 1960s due to a large number of Afro-Cubans in the Mariel boat-lift.
But even without the racial angle, younger Cuban-Americans are peeling away from the GOP on economic and cultural issues that have nothing to do with opposition to Communism. Democrats have learned to say nothing flattering about Fidel Castro. Culture matters, and Cuban-Americans are heavily Catholic. Catholics on the whole have little use for GOP pandering to Protestant fundamentalists on such superstition and pseudoscience as creationism.