Every few years a debate re-emerges on the internet as to whether university faculty have truly shifted to the left, and if so, whether it matters. The debate has just flared up because of a graph that I made after some discussions about ideology in the academy with my friend Jon Haidt, who wanted to document the trend here at Heterodox Academy. But Paul Krugman dismissed the graph and the problem on his blog at the New York Times… [I give evidence against Krugman’s interpretation]… If we compare figures 1 and 2, we see that the professoriate was changing while the electorate as a whole was not. Professors were more liberal than the country in 1990, but only by about 11 percentage points. By 2013, the gap had tripled; it is now more than 30 points. It seems reasonable to conclude that it is academics who shifted, as there is no equivalent movement among the masses whatsoever. The people who shape the minds of America’s students have long leaned left, on average. But students who entered college before 1990 could count on the fact that their professors did not all vote the same way or hold the same views on the controversial issues of the day. Students who arrived after 2005 could make no such assumption.