The Walk in Brain blog has posted a number of comments about liberal bias from university professors. Even though I try to have classes write about political and social issues, I think the only bias I give is from the deeply saddened point of view ("The president doesn't have the power to raise the minimum wage in Mexico" and "Murder is already against the law.")
I can only think of two times when I actually raised my voice about political issues. One was about animal rights which I think defies left or right status. A few students in class repeated PETA's claim that no medical advances have been made by animal experimentation. (Watch Penn and Teller's episode of Bullshit for a thorough refutation of this.) I brought up the point that the rabies vaccine was developed through animal (and human) experiments and has saved the lives of countless humans and animals (especially dogs).
They refused to believe it.
"You can argue that the advances made through animal experimentation don't justify it. You can argue that there are better ways to experiment now. You can argue that many experiments are pointless and needlessly cruel but you can't argue that no advances have been made whatsoever."
They denied it. They denied that Pasteur developed the rabies vaccine through experiments on animals AND that vaccinating dogs helped them.
I remember asking "Why do you think corporations pay millions of dollars for laboratories and to pay scientists if it never did any good? Because they care so much for the consumer?"
They stopped arguing so I'll never know for sure but I think they assumed the scientists were just being mean. This was back when "mean-spirited" was the catchphrase of the day.
The other time was about capital punishment. A group dogmatically stated that the death penalty was unconstitutional.
I pointed out that the Supreme Court ruled that the way states meted out death sentences was unconstitutional but that the ruling wasn't strictly against capital punishment itself.
None of them knew that the Supreme Court had ever struck down the death penalty but they still insisted that it was unconstitutional.
Finally I broke down and said louder than I should have that capital punishment is directly addressed in the Constitution (the Fifth Amendment to be exact) and so while it could be wrong, unfair, or immoral, it wasn't unconstitutional.
Again, I didn't change anyone's mind, just scared them into being quiet. It didn't occur to me until much later that the students thought "unconstitutional" was just another word for "mean" or "unfair." They didn't see a connection between the word and the actual Constitution at all. If I would have seen that then, I might have made myself clear.
These weren't the dumbest reactions from students (only one in about 35 students has even a foggy idea of what cloning is--many, possibly most, students think that clones have all the memories of the original organism and instantly age to become duplicates of the original).
I'm sure the students thought I was unfair and biased (although in both cases, it's more of a conservative bias than liberal). I have to wonder how much "liberal bias" is from comments like "Maybe the Trail of Tears wasn't the best decision the U.S. ever made" being interpreted as "I am a communist and hate America."