The Fifth Column
The term “fifth column” was first used by nationalist general Emilio Mola in a 1936 radio address, during the Spanish Civil War. The term simply refers to a group of people who clandestinely undermine a larger group to which it is expected to be loyal, such as a nation.

In Mola’s case, he was referring to the citizens of Madrid, who he believed sympathetic to his cause of overthrowing the legitimate government of Madrid. As Mola sent his four military columns into Madrid, he called upon his “fifth column” living in Madrid, his sympathizers, to provide aid, comfort and propaganda assistance to his soldiers, thereby assisting with their victory over Madrid’s defenses.

The term has been used many times since in many parts of the world. But it is always used to describe a clandestine “enemy within,” overtly claiming loyalty to the homeland while covertly working to undermine the homeland.

The American Fifth Column
In America, the term refers to American citizens who are ideologically aligned with anti-American organizations, sentiments, principles and values, who work individually or in concert with various organized movements in an effort to undermine American interests, counter official American policy, erode American confidence at home and abroad, or in any way aid and abet America’s enemies, while publicly proclaiming all of it to be an act of patriotism.

The most common defense for members of a Fifth Column is the claim of “conscientious objector,” or “patriotic dissenter.” This defense was used to protect draft dodgers from legal prosecution as AWOL defectors during the 1960’s. It’s been used to defend common college war-protesters as well as the American soldier who rolled a live grenade into his Commanding Officer’s tent, attacking his fellow soldiers while on deployment in the Middle East. It’s used to defend members of Congress who have traveled abroad to undermine US foreign policy and even disclose top secret military intelligence to enemies of our state.

This is the American Fifth Column and some of the many rolls they play in the destruction of a nation they publicly claim to love and support.

For years, the Fifth Column was seen as only a rag-tag group of left-leaning counter-culturalists, supporting hand-picked pieces of the International Socialist agenda, in many cases without even knowing that they were playing a vital roll in a much grander scheme. Vladimir Lenin referred to all of them as “useful idiots.” But today, what was once a clandestine movement of “useful idiots” quietly operating below radar, has become a well organized and well funded political juggernaut, largely in control of almost everything we see on TV, hear on the radio, read in newspapers, magazines and books, and even witness in the halls of congress.

The Frankfurt School
The Frankfurt School is/was a school of neo-Marxist critical theory, social research, and philosophy. The grouping emerged at the Institute for Social Research (Institut für Sozialforschung) of the University of Frankfurt am Main in Germany when Max Horkheimer became the Institute's director in 1930. The term "Frankfurt School" is an informal term used to designate the thinkers affiliated with the Institute for Social Research or who were influenced by it. It is not the title of any institution, and the main thinkers of the Frankfurt School did not use the term to describe themselves.

The Frankfurt School gathered together dissident Marxists, severe critics of capitalism who believed that some of Marx's followers had come to parrot a narrow selection of Marx's ideas, usually in defense of orthodox Communist or Social-Democratic parties. Influenced especially by the failure of working-class revolutions in Western Europe after World War I and by the rise of Nazism in an economically and technologically advanced nation (Germany), they took up the task of choosing what parts of Marx's thought might serve to clarify social conditions that Marx himself had never seen. They drew on other schools of thought to fill in Marx's perceived omissions. Max Weber exerted a major influence, as did Sigmund Freud (as in Herbert Marcuse's Freudo-Marxist synthesis in the 1954 work Eros and Civilization).

Their emphasis on the "critical" component of theory was derived significantly from their attempt to overcome the limits of positivism, crude materialism, and phenomenology by returning to Kant's critical philosophy and its successors in German idealism, principally Hegel's philosophy, with its emphasis on negation and contradiction as inherent properties of reality. A key influence also came from the publication in the 1930s of Marx's Economic-Philosophical Manuscripts and The German Ideology, which showed the continuity with Hegelianism that underlay Marx's thought. Marcuse was one of the first to articulate the theoretical significance of these texts.

The Frankfurt School is best known for a style of analysis called "critical theory." Critical theory is indebted to the ideas of German political philosopher Karl Marx in its emphasis on sources of domination and authority in society that impede the possibility of human freedom. It departs from Marxism, however, in locating the sources of domination in the realms of culture and ideology (system of beliefs), not solely in the economic structure of society. Critical theory takes the form of a critique of ideology by attempting to uncover distorting forms of consciousness, or ways of thinking. This technique draws heavily from the model of psychoanalysis proposed by the Austrian physician Sigmund Freud in its attempt to liberate people from illusions and constraints of their own making.
Sources: Wikipedia