As already known, Catalonia is currently undergoing a sovereignty issue. A social, political and institutional majority is encouraging a sovereignty process from some years ago to date, in order to found an independent Catalonian Republic. Based in Madrid, Spanish Government is trying to stop such a process, but they are not using the usual tools in politics such as the dialogue, negotiation, and covenants. Instead, they are resorting to the Constitutional Court so that this court --on the grounds of the Constitution-- annul or prohibit the different decisions made by a democratic majority in Catalonia. It seems that they in Madrid are using continuously the Constitution in force to hinder in the courts what they cannot stop with the votes in the Catalonian institutions. Is this actually true? Would it be legitimate to act this way? Are the some other similar cases? Differences aside, it seems a priori similar to the case that has already occurred in other large political transformations, such as the constituent process in Venezuela, Bolivia and Ecuador. This work aims to analyze all these cases, both in the political and the legal fields. [ABSTRACT FROM AUTHOR]