Browsing my local (Burke VA) public library recently I found the new books section prominently displaying three books complaining that universities are biased against political conservatives: Indoctrination U., Brainwashed, and Shadow University.
As I have reported before, they do seem to have a valid, if overstated, complaint: academics in top schools who teach politics-related topics are far more Democratic than Republican, and this does visibly influence their teaching and research.
Of course these facts do not imply academics are biased; perhaps their political tendencies mainly result from their expert knowledge. But surely most ordinary people do not have enough evidence to evaluate this claim one way or the other, and most political conservatives are unlikely to grant academics the benefit of the doubt on this.
It is possible that the US public will get upset enough about this apparent bias to insist on some more formal academic political neutrality, similar to the way American colonists were upset enough about European state non-neutrality on religion to insist on a formal "religious freedom" here in the US. Nevertheless, it is far from obvious that much will happen here; most societies tolerate lots of apparent biases without doing much about them.
Added: TGGP points us to some nice tables breaking this down by discipline.