The controversy over John Yoo's appointment at tenure involves, on one side, individuals who claim that his role in the "torture memos" shows him to be so incompetent, unethical, and/or immoral, that he should not be permitted to retain his position at Berkeley. On the other side, everyone from Brian Leiter to co-conspirator Jonathan Adler argue that the underlying complaint against Yoo is political, and it would be a violation of Yoo's academic freedom to threaten his tenure in the absence of an outside judgment by a bar association or court of law that he did anything beyond issuing very controversial legal advice.
My own contribution to this debate (I also wrote about the substance of a similar controversy involving Professor Delahunty in 2006, and I won't repeat my thoughts here) is going to be on the context in which this debate arises, which is that there is evidence of a strong, albeit informal, movement, among segments of the international law establishment in American law schools to decree certain "conservative" positions on international law beyond the pale of reasonable debate. I have two specific incidents in mind. My knowledge of these is based on hearsay, so I will not name the allegedly guilty parties.
First, a leading light of the international law academic establishment was asked to write a review of an entry-level international law candidate. The letter acknowledged that the candidate was bright and thoughtful, and would likely be a productive scholar, but urged the school requesting the letter not to hire the candidate because his views were too "conservative."
The second, more recent, incident arose when a candidate was being considered for a appointment at a prominent law school. All was going smoothly, until this candidate published a paper taking a controversial, though I think eminently defensible, position, on a current international law controversy. The existing international law faculty at this school swiftly rose to oppose this candidate, solely on the grounds that they were upset at the position taken in this paper, which was contrary to the "politically correct" view among left-wing international law scholars. According to my sources, the offer never materialized because of this opposition.
While Leiter is correct that it's rare for "'liberal' politicians and interest groups outside universities" to "successfully mobilize to get someone fired or even threatened that person's tenure because of conservative views," (but see, e.g., the case of UT lawprof Lino Graglia, who uttered what some deemed "insensitive" or "offensive" remarks relating to affirmative action; the result was, among other things, "Rev. Jesse Jackson flying down to Austin and a member of the (University of Texas) board of regents and a number of senators calling for him to resign"; not to mention the looming threat of "harassment" complaints and accompanying punishment at most universities if one deviates from certain orthodoxies) that's largely because academia is so dominated by the left that existing faculty have the power to deny someone a position, or tenure, to begin with if he exceeds the boundaries of what they consider acceptable discourse. One is not likely (to say the least) to get a job in a Women's Studies department if one is known to have anti-feminist views, no matter how scholarly and brilliantly argued, and, as I've noted before, as the Larry Summers fiasco at Harvard shows, anyone who wants to be president of a major university better not step outside the boundaries of political correctness.
Anyway, if the stories I've heard have been accurately described to me, Yoo is the least of one's worries about academic freedom with regard to international law. Yoo has tenure, so even claims that he is complicit in war crimes and so forth is unlikely to result in any consequences to his academic career, unless and until a bar association or other relevant disciplinary body finds that he violated his ethical duties as an attorney. But pity the entry-level or lateral candidate who dares to challenge the accepted beliefs of what I have previously termed "the cult of international law." Fortunately, legal academia is not completely closed to such individuals, but I'd hardly recommend it to an aspiring law professor.