In the beginnings of the 20th Century, many intellectuals and politicians formed political and ideological groups –not only parties– trying to change Spain, reforming the political situation and fostering democratic values in such country. Within republican groups, influenced by their French counterparts, a new generation of politicians was finally called to transform Spain in the 1930 decade. This paper is focused on the analysis of the political thought –as a sub-discipline of Political Theory– of one of them, Marcelino Domingo, firstly minister of Public Education and later head of Agriculture during the Second Republic, comparing his ideas with the ones of other republicans that influenced on the political situation in that period. Domingo developed his political ideas along the first third of the 20th century, transmitting them through his essays and literary works, where he studied not only the Spanish situation but the Italian fascism and the events of other European countries as well. In those works, we can observe his ideas about how a nation should be organized and how the political power should be exercised. According to Domingo, power could only be the will of the majority, likewise source of his concept of justice. Such approach appears coherent with the fact that Domingo, since his first participation in political life, defended democracy as the best system for modern societies.