[M]ost students will hear next to nothing about the conservative tradition in American politics that stretches from John Adams to Theodore Roosevelt to William F. Buckley Jr. to Milton Friedman to Ronald Reagan. This tradition emphasizes moral and intellectual excellence, worries that democratic practices and egalitarian norms will threaten individual liberty, attends to the claims of religion and the role it can play in educating citizens for liberty, and provides both a vigorous defense of free-market capitalism and a powerful critique of capitalism's relentless overturning of established ways. It also recognized early that communism represented an implacable enemy of freedom. And for 30 years it has been animated by a fascinating quarrel between traditionalists, libertarians and neoconservatives.
While ignoring conservatism, the political theory subfield regularly offers specialized courses in liberal theory and democratic theory; African-American political thought and feminist political theory; the social theory of Karl Marx, Emile Durkheim, Max Weber and the neo-Marxist Frankfurt school; and numerous versions of postmodern political theory.
I want to say at the outset that I am and have long been in favor of greater integration of conservatives in the academic sphere (I've publicly called for diversity affirmative action for conservatives in highly liberal academic environs, a move that Berkowitz actively disclaims support for). But I'm not 100% convinced the problem is as stark as Berkowitz makes it out to be.
First, we do need to observe that at least portions of the conservative movement, comprising some of its most prominent public writers, bitterly decry "liberal bias" in the academy, but show an utter blindness as to what sorts of conservatives are intellectually sophisticated enough to merit inclusion in a high-level college political theory course. The folks that Berkowitz mentions (Roosevelt, Buckley, Oakeshott) certainly qualify. But I recall a poster featuring such "distinguished" academic lights as Ann Coulter, Dineesh D'Souza, Robert Novak, and Michelle Malkin with the tag "no education is complete until it includes us." Well, no -- I can't think of a single political theory course, including one specifically focusing on modern conservative thought, that would not be drastically diminished by the inclusion of Ann Coulter. To the extent that this is what some conservatives (presumably not Berkowitz) mean when they complain about their exclusion from academic halls, my sympathy is rather dramatically curtailed. The definitive anti-intellectual turn (see also) trumpeted by at least some modern conservatives is a barrier to including conservatives in any form they'd recognize as valid.
Second, I'm not hugely convinced conservatives are absent from political theory courses, at least those which are broad enough in scope so as to include a broad swath of political schools (I would agree that it would be interesting to have a course that focuses specifically on conservative political thought). I only have my own Carleton experiences to go on, of course, but let's run through the authors I read in "Introduction to Political Philosophy": Plato, Aristotle, Machiavelli, Hobbes, Locke, Rousseau, Burke, Mill, Marx. Plenty of names on their that conservatives would be happy about. My "Justice and Politics" class opened with a unit on libertarianism and was heavily invested in the Rawls/Nozick debate. My American Political Thought class, too, seemed to give the ideas that Berkowitz wanted aired their proper due. The thing here is that it's always possible to name another writer that wasn't on a syllabus -- an "inexcusable omission". But given that there is a limited amount of time, and allowing professors some leeway to teach courses from the angle that most interests them,* I'm not sure that conservative ideas are being short-changed.
Finally, I want to register a serious quibble I have with Berkowitz putting "conservative political thought" as a polar opposite of "African-American political thought". Obviously, as someone interested in Black Conservatism and Nationalism, I'm annoyed at this dichotomy. And it's not just my own idiosyncratic pursuit. I took a course in the Foundations of African-American Political Thought: The primary authors we read were Frederick Douglass, Booker T. Washington, W.E.B. Du Bois, Alain Locke, and Marcus Garvey. I think both Douglass and Washington could rest comfortably in Berkowitz's conservative tradition; I also think you can make an argument that Garvey's Nationalism lies closer to it than it does to a Du Boisian liberalism. Between the fact that Berkowitz names solely White authors and the fact that he expressly casts African-American Political Thought as being a course one does instead of a course that might draw attention to conservative ideas, one gets the disturbing intuition that Berkowitz "doesn't count" Black Conservatives as genuine figures in his movement. But if Berkowitz is going to short-change his own side, no wonder he feels so lonely!
* My APT professor's primary research interest is in early 20th century American pragmatism, hence the Du Bois/Lippmann/Dewey stress. But interestingly, despite all being "liberals", they are very attuned to "moral and intellectual excellence, worries that democratic practices and egalitarian norms will threaten individual liberty, and atten[tion] to the claims of religion and the role it can play in educating citizens for liberty" -- the former two being the subject of my final paper for that class.