Mark Bauerlein, a professor of English at Emory University writes on the effects of left wing groupthink at universities, and the effect it has on career advancement and curriculum.
Yet while the lack of conservative minds on college campuses is increasingly indisputable, the question remains: Why?
The obvious answer, at least in the humanities and social sciences, is that academics shun conservative values and traditions, so their curricula and hiring practices discourage non-leftists from pursuing academic careers. What allows them to do that, while at the same time they deny it, is that the bias takes a subtle form. Although I’ve met several conservative intellectuals in the last year who would love an academic post but have given up after years of trying, outright blackballing is rare. The disparate outcome emerges through an indirect filtering process that runs from graduate school to tenure and beyond.
Some fields’ very constitutions rest on progressive politics and make it clear from the start that conservative outlooks will not do. Schools of education, for instance, take constructivist theories of learning as definitive, excluding realists (in matters of knowledge) on principle, while the quasi-Marxist outlook of cultural studies rules out those who espouse capitalism. If you disapprove of affirmative action, forget pursuing a degree in African-American studies. If you think that the nuclear family proves the best unit of social well-being, stay away from women’s studies.
Other fields allow the possibility of studying conservative authors and ideas, but narrow the avenues of advancement. Mentors are disinclined to support your topic, conference announcements rarely appeal to your work, and few job descriptions match your profile. A fledgling literary scholar who studies anti-communist writing and concludes that its worth surpasses that of counterculture discourse in terms of the cogency of its ideas and morality of its implications won’t go far in the application process.
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The first protocol of academic society might be called the Common Assumption. The assumption is that all the strangers in the room at professional gatherings are liberals. Liberalism at humanities meetings serves the same purpose that scientific method does at science assemblies. It provides a base of accord. The Assumption proves correct often enough for it to join other forms of trust that enable collegial events. A fellowship is intimated, and members may speak their minds without worrying about justifying basic beliefs or curbing emotions.
[…]
After Nixon crushed McGovern in the 1972 election, the film critic Pauline Kael made a remark that has become a touchstone among conservatives. “I don’t know how Richard Nixon could have won,” she marveled. “I don’t know anybody who voted for him.” While the second sentence indicates the sheltered habitat of the Manhattan intellectual, the first signifies what social scientists call the False Consensus Effect. That effect occurs when people think that the collective opinion of their own group matches that of the larger population. If the members of a group reach a consensus and rarely encounter those who dispute it, they tend to believe that everybody thinks the same way.
[…]
The final social pattern is the Law of Group Polarization. That law, as Cass R. Sunstein, a professor of political science and of jurisprudence at the University of Chicago, has described, predicts that when like-minded people deliberate as an organized group, the general opinion shifts toward extreme versions of their common beliefs. In a product-liability trial, for example, if nine jurors believe the manufacturer is somewhat guilty and three believe it is entirely guilty, the latter will draw the former toward a larger award than the nine would allow on their own. If people who object in varying degrees to the war in Iraq convene to debate methods of protest, all will emerge from the discussion more resolved against the war.
The full article is here.

After graduate school, and before escaping to the private sector, I spent 12 years in university and government laboratories. I can verify that this article absolutely NAILS the political culture of academia. It describes especially well the way that left-wing political conformity is enforced by making non-conformers feel socially uncomfortable and alien. It is a problem that is dangerous partly because it is so insidious.