I believe that Cuba would be free today BUT FOR the actions of the Cuban-American hard-liners.
For decades the U.S. had two very different foreign policy approaches to certain Communist regimes. Since 1961, we isolated Cuba with our total embargo - prohibiting trade, cultural exchanges, tourist visits - and we tried to get our various allies around the world to honor the U.S. embargo.
We did the opposite in Eastern Europe while those countries were still under the control of the former Soviet Union. For Eastern European countries, we sent orchestras, ballet troupes, cultural exchanges, sports teams, visiting professors, poets, writers, trade and commerce. All of those many many many thousands of individual contacts over the decades between "free" visiting U.S. and western people and the local Eastern European populations planted the seeds of freedom in the minds of the Eastern Europeans. When conditions lightened in the 1980s, those Eastern European populations, particularly the educated "elites", the "intelligentsia", the poets and writers, already yearned for freedom and quickly threw off their Soviet oppressors (and local oppressors who were Soviet-imposed). Their populations had already known of the cultural, economic and political freedoms and benefits of the West and the U.S.
By isolating Cuba and through our U.S. embargo making the lives of ordinary Cubans very harsh and deprived, the U.S. hard-liners have propped up the oppressive Castros over the years. The Castro government could always point to the U.S. embargo as the cause for this or that hardship experienced by ordinary Cubans - less food, cars, gasoline, electricity, modern machinery.
If we had applied the same policy to Cuba as we had applied to the populations of Eastern Europe over the decades, the Cuban population - the man and woman on the street - would have seen the 1989 collapse of the Berlin Wall and the Soviet Iron Curtain in Eastern Europe and would have thrown off their own similar oppressors in short order after each of the Eastern European countries did so.
Hard line old guard Cuban-Americans, almost uniformly right wing Republicans, have required every Republican nominee since President Eisenhower to pledge allegiance to the embargo against Cuba, preventing application to our Cuban policy of the successful policy we used in Eastern Europe.
Cuba today would be having its third or fourth free election for its national leaders and parliament - like Eastern European countries are doing - instead of still being under the yoke of the oppressive unelected 83 year old Communist Raul Castro.