I think most professors at schools in Oklahoma have come to terms with their students being majority conservative and keep it toned down. I would guess the situation is much different in areas such as Oregon where the split in the actual class trends towards liberal.
You make a valid point. I do tend to believe there are real regional differences. My oldest daughter, who also lives in Oklahoma considers herself to be a “liberal Democrat”. But, in our discussions around the kitchen table, she was very quick to point out that a “liberal” from Oklahoma and a “liberal” from Massachusetts or San Francisco are 2 different animals. Her words, not mine.—JM