The aim of this essay is to clarify some aspects of Walter Lippmann's reflection on democracy, focusing on his writings of the Twenties. Better known for his work as a journalist than for his books on "public philosophy", Walter Lippmann (1889-1974) was an acute political thinker, whose main interest was to investigate the possibilities for democracy in 20th century mass societies. The paper shows that this issue constitutes a key problem in Lippmann's thought not only in the age of totalitarianism, but from the very beginning of his career. Moving from his education at Harvard and his political engagement in the progressive era, the essay shows how Lippmann's collaboration with Woodrow Wilson's administration during World War I was crucial in determining his interest in propaganda and public opinion. Only marginally was it a journalist's reflection on the status of his profession; instead, it was a deeper and more philosophical re-consideration of the foundations of both the theory of knowledge and of democracy. Starting from the lessons of Socrates and Plato and criticising liberal and democratic political thought from the 18th century onwards, Walter Lippmann investigated in his 1920s writings the relationship between public opinion and democracy, arguing finally that the "myth of the omnicompetent citizen" was a fallacy and that the public was a "phantom". Following these conclusions, Lippmann focused his attention on the role of political elites, journalists and social scientists, advocating a sort of technocratic model with relevant similarities to the theory of democratic elitism developed by Joseph A. Schumpeter in 1942. It will then be shown how Walter Lippmann's reflection from 1925 to 1928 grew even more pessimistic and critical against classical democratic theory, emphasising his lack of confidence in the common man's ability to understand the world's problems and to manage them. In this context, Lippmann developed a relevant critique of the theory of majority rule, against the risks of fundamentalist and revisionist attacks.