Democratic Jacobinism is an illiberal doctrine precisely because it subordinates everything to a single force, that of the so-called majority, on which it does not set any limits.

During this time, Mosca also worked as a political journalist for the Corriere della Sera of Milan (after 1901) and the Tribuna of Rome (from 1911 to 1921).

On numerous occasions, the elderly Mosca took to the floor to speak against bills endorsed by Benito Mussolini which intended to curtail political rights and parliamentary institutions.

[6] Parliamentary regimes were able to protect civil and political liberties because they provided an independent source of authority through which to limit the power of the rulers.

[6] Mosca's speeches in support of civil liberties and parliamentary government, as well as his steadfast refusal to compromise with the fascist regime, exerted an important influence on members of the intellectual opposition to Mussolini's dictatorship such as Gaetano Salvemini and Piero Gobetti.

Defunct Mosca's enduring contribution to political science is the observation that all but the most primitive societies are ruled in fact, if not in theory, by a numerical minority.

This concept originated from his materialist idea of history as a conflict between classes (Marx), from the conflictual nature of politics considered as a fight for acquisition and deployment of power (Machiavelli), and finally from the non-egalitarian, hierarchical structure of society.

Unlike Marx, Mosca has not a narrow concept of historical time, but a circular one, as in classical political theory, which consists in a perpetual condition of conflict and recycling of the elite.