Socialism, as expressed by political parties professing that ideology, has had only minimal impact on Argentina's twentieth-century political history. On the other hand socialist ideas, broadly defined, have had considerable influence, although often in an indirect manner. In the political realm, for example, popular presidents Hipólito Yrigoyen (1916-1922; 1928-1930) and Juan Perón (1946-1955; 1973-1974) sought to pre-empt and co-opt socialism's appeal to the working class by proposing and implementing socialist-inspired reforms wrapped in nationalist rhetoric. Conversely, after the fall of Perón in 1955 various military governments have based their intervention into national politics largely on the need to stem the flow of Marxist ideas, to prevent the growth of socialist organizations—especially those which would repeat the Cuban revolutionary experience on Argentine soil—and to protect the principles of free enterprise capitalism.