Starting from the statement that there is a close link between the idea of the «border» (and more generally of any kind of «boundary») and a notion of citizenship whatsoever, the author analyses, among many possible meanings, two «ideal types» which have differently had a part in the process of modern State building, contributing to clarify that the citizenship has to do with the idea of separation, exclusion and difference, much more than with the idea of integration and inclusion. The citizenship can be conceived in a «vertical» meaning, that is a relationship between the individual and the sovereign, or in a «horizontal» meaning, that is a collective identity, binding all individuals on the basis of a common political membership. After following the «great neutralisation» of the Nineteenth Century, when citizenship changes into a new «national» dimension, becoming properly a «nationality», the author focus on two clear examples of «political use» (or, as we could also say, «political manipulation») of the notion of citizenship: in USA at the time of the adoption of XIV Amendment in 1865 and in France, between the end of Napoleonic Age and the middle of Twentieth Century. At that time the border plays a new role, including and excluding from time to time new categories of people, depending on political and historical needs of the moment. Some considerations
are finally developed about the political relationship between citizenship and the notion of border in the Twentieth Century’s Constitutional State, when the idea of a «national» citizenship, sometimes as vertical relationship between the individual and the State, sometimes as consciousness of a collective membership, is still at the heart of our legislation, with the political aim to keep the distances, and
strenuously defend the borders, between the «lucky» citizens of the rich developed world from one side, and the new «wretched of the Earth» from the other side.