Should there be limits on teachers' freedom of speech?

Teachers who address controversial topics in the classroom -- Darwinism and evolution, for instance, or anything else that touches religion or politics -- may find it pays to keep their mouths shut. In Arizona, Senate Bill 1542 aims to forbid educators from advocating for one side of any social or political issue, claiming that students are impressionable and this sort of thing may encroach on parental territory.

Must teachers, by the very nature of their profession, place stricter limits on their ability to express opinions in the workplace? Or are the kinds of free-speech struggles that teachers face unwarranted and undeserved? Tell us what you think. -- Sara Bernard