Read that. Give it consideration as to what would happen if we in Canada, the USA, and other western "democracies" had the sense to conduct elections in a similar fashion and get political parties themselves out of the process entirely! We would, by golly, have very inexpensive, simple, and uncorrupted elections, and our chances of creating a truly representative and honest government would go up by about 500%, in my opinion.
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You are correct that the Cuban republic identifies itself as a One-party system, but that party does not select the candidates who run in Cuban elections. The ordinary public selects the candidates, in a free and completely open manner.
Your comment that the USA actually has a One-Party system is apt...and quite correct. It's the USA-ian Corporatist/Military Party, in truth, but it masquerades as 2 separate parties, Democrats and Republicans, and DOES control the selection of candidates and makes them beholden to corporate funding from the getgo, so that once in office they will serve the Corporatocracy.
That's pretty much the diametrical opposite of what is done in Cuba, where elections are extremely inexpensive, where candidates run on their individual merits and record, NOT on party affiliation, and NOT with any financial advantage over competing candidates. The only advantage a candidate can have in Cuba over another candidate aiming for the same office is this: Do the voters in that region have greater confidence in his or her honesty and abilities than they do in the other candidates for that office? If so, he or she will win. That's it. Period. There is no way to corrupt and subvert a system as simple and transparent as that.