I have no doubt that the government in Cuba has mass support. However, to have two brothers run the country with no method to affirm them in their position.
Under their system they are affirmed by the officials elected at the lower levels. Sort of like voting for an MP and then they decide who is going to be the PM. On paper the people run as independents not for any political party including the Communist Party.
CHAPTER X
SUPREME ORGANS OF PEOPLE’S POWER
ARTICLE 69
The National Assembly of People’s Power is the supreme organ of State power and represents and expresses the sovereign will of all the working people.
ARTICLE 70
The National Assembly of People’s Power is the only organ in the Republic invested with constituent and legislative authority.
ARTICLE 71 The National Assembly of the People’s Power is comprised of deputies elected through a free, direct, and secret ballot by the voters, in the proportion and according to the procedure that the law establishes.
ARTICLE 72 The National Assembly of People’s Power is elected for a period of five years. This period can only be extended by virtue of a resolution of the Assembly itself in the event of war or in the case of other exceptional circumstances that may impede the normal holding of elections and while such circumstances exist.
ARTICLE 73 The National Assembly of People’s Power, upon convening for a new legislature, elects from among its deputies its President, Vice President, and Secretary. The law regulates the manner and procedure whereby the Assembly convenes and holds that election.
The problem with constitutions isn't what they say but with the reality behind them. The Soviet constitution of 1936 guaranteed freedom of religion and the right of all the republics to secede. However, most scholars and historians would not agree those were real rights that could be a exercised. For example all the republics had an ethnic Russian occupying the vice president position and exercising real power. The Canadian constitution is another case in point. The PM is theoretically not much more than the " first among equals". But of course that really isn't true as the PM is one of the most powerful executives in any western democracy. For example their signature is required for any candidate running under their party's banner. If the PM does not want them as a candidate they are out. A power the US president doesnt have. So anyone reading our constituion to develop an idea of how our politics works would be surprised by reality. My reading of Cuba is that Castrohad levers not necessarily described within th constitution.