Lippmann was a prominent socialist from his youth, becoming president of the Harvard Socialist Club and a member of the Executive Committee of the Intercollegiate Socialist Society. He graduated from Harvard in 1910, but took his socialism with him into his journalism, joining the Socialist Party and the Socialist Press Club. More than 20 years later, with the election of President Franklin Roosevelt, Lippmann apparently lost faith in the Constitution, telling FDR, "The situation is critical, Franklin. You may have no alternative but to assume dictatorial powers"; in his column, Lippmann added that the use of "'dictatorial powers,' if that is the name for it—is essential."
Lippmann retained his socialist sympathies even in the midst of the Nazi-Soviet Pact, when "WJL" [Walter J. Lippmann] wrote to "ECC" [Edward C. Carter]—head of the Communist-front "American Russian Institute" and Institute of Pacific Relations ("a vehicle used by the Communists to orientate American far eastern policies toward Communist objectives," according to a unanimous report of the bipartisan Senate Judiciary Committee)—urging "cooperation with the European revolutionaries and the Soviet Union in their attempt to build a socialist Europe as a nucleus for a world socialist order, with the obvious corollary of the establishment of socialism in this country."
Until 1943, Lippmann's secretary was Mary Price, a Soviet agent. Lippmann himself was a Soviet intelligence source as late as 1944. According to Eric Alterman, a columnist and blogger for The Nation, Lippmann "offered much more useful information to the Soviets than [I.F.] Stone ever did."
He has also been highly praised with titles ranging anywhere from "most influential" journalist of the 20th century, to Father of Modern Journalism. James W. Carey, an influential teacher of journalists, considered Walter Lippmann's book Public Opinion as "the founding book of modern journalism" and also "the founding book in American media studies".
Lippmann attended Harvard College, where he studied with the leading philosophers of the day, including George Santayana, William James, and Fabian Socialist Graham Wallas. His first job was helping muckraker Lincoln Steffens on Everybody's Magazine. He became active in the Socialist party and was one of the founding editors of The New Republic magazine in 1913.
He agreed with Theodore Roosevelt that the purpose of diplomacy was not to attempt the impossible but to deal realistically with the existing balance of power. During World War I he was a staff assistant to Secretary of War Newton D. Baker, and a special adviser to Colonel House, President Woodrow Wilson’s top foreign policy advisor. Lippmann helped draft Wilson’s Fourteen Points in 1918, which became the basis for ending the war and restructuring world affairs at the Paris Peace Conference in 1919, where he was advisor to House. In the 1920s he was editorial page editor of the influential Democratic newspaper the New York World, and sharply criticized the foreign policy of Harding and Coolidge for ignoring the League of Nations. When the World closed in 1931 he started his newspaper column Today and Tomorrow for the Republican paper the New York Herald Tribune. It was syndicated to 200 dailies across the country and continued until 1967.
In the 1920s philosopher John Dewey (1859-1952) engaged in a major debate with Lippmann on the impact of the technology on democracy. Both agreed that the communications revolution had created a large and more complex world, that political and social institutions had not kept pace with the changes wrought by technology, that the masses were more susceptible to propaganda, and that modernity threatened democracy. Their critiques diverge on solutions, especially whether or not democracy could be saved. While Lippmann saw the public as unredeemable and subject to mass manipulation, Dewey thought that more public involvement in socio-political affairs was needed and that tools of mass communication could be used to this end.
Manipulation of Public Opinion
In 1922, Walter Lippmann published his book "Public Opinion"  which at the time presented a major milestone in marking the ability of a journalist to manipulate their readers and viewers. The phrase "Manufacture of Consent" is directly attributed to Walter Lippmann  from his book "Public Opinion". He wrote: 
That the manufacture of consent is capable of great refinements no one, I think, denies. The process by which public opinions arise is certainly no less intricate than it has appeared in these pages, and the opportunities for manipulation open to anyone who understands the process are plain enough.
Lippmann went very far into detail of these methods of manipulation. He gives uses of keywords, for the use of tapping into people's stereotypes, and the use of editorials afterwards to make sure that the pre-determined outcome is assured. He fully understood the opportunities for manipulation and detailed the process. Here is one such example: 
It is a problem of provoking feeling in the reader, of inducing him to feel a sense of personal identification with the stories he is reading. News which does not offer this opportunity to introduce oneself into the struggle which it depicts cannot appeal to a wide audience. The audience must participate in the news, much as it participates in the drama, by personal identification. Just as everyone holds his breath when the heroine is in danger, as he helps Babe Ruth swing his bat, so in subtler form the reader enters into the news. In order that he shall enter he must find a familiar foothold in the story, and this is supplied to him by the use of stereotypes. They tell him that if an association of plumbers is called a "combine" it is appropriate to develop his hostility; if it is called a "group of leading business men" the cue is for a favorable reaction.
It is in a combination of these elements that the power to create opinion resides. Editorials reinforce.
To this day, the aggressive use of keywords and stereotypes is widely used by the journalist establishment.
In 1937 Lippmann attacked President Franklin D. Roosevelt's plan to reorganize the Supreme Court, which reflected Lippmann's growing criticism of the New Deal. Although he originally supported Roosevelt's policies, Lippmann felt that the president was placing the American constitutional system in danger by setting illegal precedents.
Lippmann is accredited with popularizing the phrase "Cold War" to describe the breakdown of the World War II Allied Powers alliance and the growing post-war tensions. Although he opposed Communism he adopted a "realist" position in foreign policy in the 1940s and opposed idealistic goals such as Wilsonianism-- even though he had been a leading advocate of idealism in 1917-1918. He was distrustful of globalism or excessive involvements around the world. In the 1960s he was an articulate opponent on the War in Vietnam, saying it weakened America's ability to fight the true Soviet adversary.
- Blum, D. Steven. Walter Lippmann: Cosmopolitanism in the Century of Total War. (1984). 205 pp.
- Riccio, Barry D. Walter Lippmann - Odyssey of a Liberal. (1994). 240 pp.
- Steele, Ronald. Walter Lippmann and the American Century (1980), 599pp; the standard biography
- Wright, Benjamin F. Five Public Philosophies of Walter Lippmann. (1973). 171 pp.
- Lippmann, Walter. Public Philosopher: Selected Letters of Walter Lippmann, edited by John Morton Blum (1985)
- Lippmann, Walter. The essential Lippmann: a political philosophy for liberal democracy ed by Clinton Rossiter (1963) excerpt and text search, selection of conservative essays and excerpts
- Lippmann, Walter. Early Writings ed. by Arthur Schlesinger, Jr. (1970), liberal essays from New Republic down to 1920; reprinted as Force and Ideas: The Early Writings
- Lippmann, Walter. Drift and mastery: an attempt to diagnose the current unrest (1914) full text online
- Lippmann, Walter. A preface to politics (1914) 318 pages online edition
- Lippmann, Walter. Drift and mastery: an attempt to diagnose the current unrest (1917) 334 pages online edition
- Lippmann, Walter. Public Opinion (1922) 427 pages online edition
- Lippmann, Walter. Men of Destiny (1927)
- Lippmann, Walter. Interpretations: 1931-32 (1932), newspaper columns; still a liberal
- Lippmann, Walter. Interpretations: 1933-35 (1935), newspaper columns, still a liberal
- Lippmann, Walter. The Good Society (1937), his statement of conservative values excerpt
- online books by and about Lippmann
- books by Lippmann
- His name is often misspelled with only one 'N'--as for example the Time cover shown here.
- Lippmann is widely regarded as “the most influential journalist in American history.” Jacqueline Foertsch, American Culture in the 1940s (Edinburgh University Press, 2008) ISBN 0748624139, p. 56
- "Joined the Harvard Socialist Club and later became president... Elected to Executive Committee, Intercollegiate Socialist Society... Joined the Socialist Party, New York County, and the Socialist Press Club of New York City." (2003) Twentieth-Century American Politics and Diplomacy, Series 1, The Walter Lippmann Papers, Part 4: Early Papers, 1904-1920 (Manuscript and Archives Division, Sterling Memorial Library, Yale University, New Haven, Connecticut), pp. 8-9
- Thomas Griffith, “NEWSWATCH: Comrade of the Powerful,” Time, September 15, 1980
- Russell Baker, “A Revolutionary President, The New York Review of Books, Vol. 56, No. 2 (February 12, 2009)
- S. Rpt. 2050, 82d Cong., 2d sess., Serial 11574, Report of the Committee on the Judiciary Pursuant to S. Res. 366, 1952, p. 225 (PDF p. 233)
- Walter Lippmann to Edward C. Carter, June 10, 1940, p. 5 (PDF p. 100), FBI file: Institute of Pacific Relations, Section 54, Part 11, pp. 96-101
- 588 New York to Moscow, 29 April 1944; cf. Institute of Pacific Relations Hearings, Part 2, Subcommittee to Investigate the Administration of the Internal Security Act and Other Internal Security Laws, Committee on the Judiciary, United States Senate, 82d Cong., 1st Sess. (Washington: United States Government Printing Office, 1951), p. 406 (PDF p. 62); Romerstein, Breindel 2001: 439 and Haynes, Klehr 1999: 99
- 1289 KGB New York to Moscow, 9 September 1944
- Walter Lippmann and American journalism today (31 October 2007).
- Drucker Gives Lippmann Run As Most Influential Journalist. Chicago Tribune (1998).
- Walter Lippmann and the American Century (1980).
- (2011) The Filter Bubble: How the New Personalized Web Is Changing What We Read and How We Think. New York: Penguin. ISBN 0143121235.
- (2003) Information War: American Propaganda, Free Speech and Opinion Control Since 9/11. Canada: Seven Stories, 30–31. ISBN 1583225579.
- In Memoriam, James W. Carey (2006).
- Schudson, Michael (2008). "The "Lippmann-Dewey Debate" and the Invention of Walter Lippmann as an Anti-Democrat 1985-1996". International Journal of Communication 2.
- Carey, James W. (March 1987). "The Press and the Public Discourse". The Center Magazine 20.
- Walter Lippmann, Public Opinion (1922) and The Phantom Public (1925); John Dewey, The Public and Its Problems (1927)
- Walter Lippmann, Public Opinion
- p. 13, Noam Chomsky, Letters from Lexington: Reflections on Propaganda, Paradigm Publishers 2004.
- Walter Lippmann, , p. 248
- Walter Lippmann, , p. 355
- Frederic Krome, "From Liberal Philosophy to Conservative Ideology? Walter Lippmann's Opposition to the New Deal" Journal of American Culture 1987 10(1): 57-64. 0191-1813
- The Golos spy ring used Mary Price, his secretary, to garner information on items Lippmann chose not to write about or names of Lippmann's sources, often not carried in stories, but of use to the MGB.
- Fredrik Logevall, "First Among Critics: Walter Lippmann and the Vietnam War." Journal of American-East Asian Relations 1995 4 (4): 351-375.
- Religion, Politics, and the Higher Learning, Morton White, Harvard University Press, 1959 p.112