Miami-Dade County is rapidly becoming a nightmare for the GOP. With 2012 turnout patterns Crist wins the state by at least 2-3%. The oldest Cubans are about 65% R or more while the youngest ones seem to vote D at the same rate as other Hispanics.
http://www.nytimes.com/2014/12/18/upshot/why-the-cuba-issue-no-longer-cuts-against-democrats-in-florida.html?rref=upshot&_r=0The embargo shouldn't be a big issue and change things much. Dade County I can see becoming a 67-75% Democratic county in the future that will anchor Florida Democratic wins.