I do not believe academic freedom has become skewed in one political direction at American universities. I believe American universities are very good about being opened and honest and I also think they given students the opportunity to speak about their own opinions and discuss them out loud. I haven't noticed any problems with bias in this environment.
Certain major universities can clearly be defined as following one political ideology or another, but to say that one side of the coin is dominating would be a mistake. For ever major liberal arts, left leaning university out there, there is a conservative religious university with old fashioned values and rules being preached.
I do not think that academic freedom has been skewed in American colleges. I believe that there are many different methods being taught in colleges. The methods and content of the classes vary greatly depending on the type of college and the professor that is teaching the course. I have not seen any restrictions or political pressure being put on the academic freedom in colleges.
There's this bizarre fear that the university educated are being taught more left-wing values than right-wing ones, yet the fact that there's no huge majority in politics as these educated people grow older, graduate, and continue to participate in our political process, is telling that this fear is nothing more than a myth.
No, academic freedom has not become skewed in one political direction at American universities, because there is a balance. There are some universities that are very liberal, and others that are very conservative. I attended Georgetown University, and I found a very thoughtful balance of liberals and conservatives among professors.