Here is an article from the Duke Conservative Union on the issues that school is having with Intellectual Diversity there.

Much to the dismay of the Duke administration, the DCU has provoked its ritual annual contretemps, this time by publishing an advertisement revealing that registered Democrats outnumber Republicans by a whopping 142-to-8 margin among university deans as well as faculty members of eight liberal arts departments. The numbers apparently startled some alumni-donors, which provoked President Keohane to publish a soothing article declaring that the near monopoly Democrats enjoy in the humanities, of course, in no way implies any insincerity regarding her oft-stated commitment to intellectual diversity.
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Unlike Professors Thompson and Quilligan, VP Burness acknowledged the predominance of liberals in the surveyed departments, which he explained by citing the need for “creativity” and “innovation” in the humanities, qualities that are apparently in short supply among conservatives. Philosophy Department Chairman Robert Brandon voiced a similar explanation, although in less diplomatic terms: “If, as John Stuart Mill said, stupid people are generally conservative, Editorial then there are lots of conservatives we will never hire. Mill’s analysis may go some way towards explaining the power of the Republican party in our society and the relative scarcity of Republicans in academia. Players in the NBA tend to be taller than average. There is a good reason for this. Members of academia tend to be a bit smarter than average. There is a good reason for this too.”
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The ultimate irony is that by uttering such inane comments and thereby turning himself into a national laughingstock, Professor Brandon undermined his essential point that academics are smart. Thus, he cleverly managed to disprove his own argument merely by stating it. In fact, the entire argument, coming from a hiring committee member, that few conservatives get hired not due to any bias in the hiring process, but rather because many conservatives are stupid, also serves to refute itself. Professor Brandon apparently does not realize the difficulty of agreeing with a person who doesn’t even agree with himself.

Here is more on this controversy from Instapundit. Of course, this is really just the tip of the iceberg as Duke is not the only place where this is a problem.