There is a belief that college campuses tend to be liberal. That would make one think that college professors are likely to be liberal. So one would expect that if that is true, college professors would vote for liberal candidates.
This study says that professors are getting more liberal. THe study is conducted every three years, or so, and finds that professors are more liberal than before. Only 12% of professors are conservative or far right. 63% are liberal or far left. 25% consider themselves middle of the road.
You can draw your own conclusions about how they might vote.