Experts debate whether constitutions or international treaties have to be seen as the highest norm of a particular legal system. However, a compromise has been reached according to which some topics contained in international treaties, such as the protection of human rights (including of course political and voting rights which are part of the so-called “second generation” of human rights), have to be included within any nation’s legal system. Otherwise, such a nation can be seen as unconstitutional and undemocratic.

International treaties, which are now mandatory for more and more countries, have promoted and consolidated political and voting rights. Among such treaties, some can be listed as follows: the Universal Declaration of Human Rights, the American Declaration of the Rights and Duties of Man, the International Covenant on Civil and Political Rights, the American Convention on Human Rights (also known as the San Jose Convention), and the Convention on the Political Rights of Women.

International documents are an important source of electoral law. It is impossible to underrate the high number of international covenants, resolutions, charts, declarations and reports related to human rights in general and to political rights in particular. Many important rules are derived from international documents. For instance, every democratic country has to vote the appointment of its representative officials. In the same line of reasoning, international documents enhance the importance of international observers in electoral processes.

International documents are regulated by specialized rules of international law. However, treaties in particular have to be adopted by national constitutions. National constitutions must see international treaties as producers of national laws, as higher regulations, as mandatory norms. Ordinary legislation and regulation have to detail both the content and procedural issues established by international treaties.

According to some rules derived from the Vienna Convention on the Law of Treaties, (1969), there are three main principles regulating this topic: a) Every treaty bounds the states which approved it; b) No State can be bound by a treaty which has not been approved by it; and c) Convened obligations are based on the consent of the states. 

International treaties are so important in the world that it is very difficult to think of a national rule or constitutional norm (particularly in the field of electoral and political rights) that can oppose them. Democratic constitutional states do recognize and adopt international documents in their internal legal system.