From The Weekly Standard, The Roots of Campus Leftism by Warren Treadgold

The absence of reasoned argument is in fact one of campus leftism’s sources of strength. Refusing to supply ideological definitions leaves the impression of a viewpoint that depends not on arguments that in theory could be refuted but is instead so obvious to every decent person that it needs no support from logic or reason. The implication is that campus leftists favor a set of principles that transcend ideology, for which the appropriate name is simply “social justice” or “the truth.” Campus leftism is more a matter of feeling than of thought and is based more on passion and outrage than on reasoning. Counterarguments are shouted down on the ground that they offend or discriminate against favored members of the campus community, while disfavored members of the community receive no sympathy if they claim to be offended or discriminated against.

Although it may seem pointless to look for intellectual content in campus leftism, it really is an ideology, and it has intellectual roots. Its guiding principle is the Marxist concept that people are divided into classes of oppressors and oppressed. According to classical Marxism, the oppressors are the exploiting capitalists or landowners, who represent the “class enemy”; their victims are the working classes, otherwise known as “the people,” with the implication that their class enemies are less than human. The oppressors must be resisted, and the oppressed defended, by any means necessary. While Stalin, Mao, and Pol Pot killed large numbers of supposed oppressors, less extreme Marxists believed the job could be done by limiting the oppressors’ legal rights, including their right to free speech. In the case of universities, in most Communist countries people from the wrong class background were either denied admission to higher education or allowed only restricted access to it, while those from the correct class backgrounds received preference in admissions and hiring.