Venezuela's leader-only regime change and tariff threats to Mexico are all about choking off oil to Cuba, in service of the ambitions of Marco Rubio and neocon-inspired Monroe Doctrine neocolonial imperialist aspirations of placing the entirety of the Americas under the boot of the USA... countries are free to hold elections so long as their leader's views and policies are aligned with Washington's or else the CIA coups, kidnappings, airstrikes, and/or tariffs happen.
Cuba is a dictatorship that has imprisoned and murdered thousands of its own citizens. Socialism inevitably falls toward dictatorship as people stop working under it.
What really is the point in maintaining a blockade after the end of the cold war?