An interesting post at HeterodoxAcademy.Org shows that college professors have become more liberal since the 1990’s. Sam Abrams analyzed data from the Higher Eduction Research Institute--samples that contain thousands of faculty. The graph produced by Mr. Abrams is below.
Please see: http://heterodoxacademy.org/2016/01/09/professors-moved-left-but-country-did-not/
John Paul Wright and Matt DeLisi
Professors of Crime and Criminology