When the local school board was considering a freeze in teacher salaries

When the local school board was considering a freeze in teacher salaries, a high school journalism teacher decided to write a "letter to the editor" condemning the actions of the board. The letter is published in the local newspaper. He then required his journalism students to also write letters to the local newspaper criticizing the salary freeze proposal for teachers. He was terminated for his actions. Should he have been terminated for his actions? Why or why not?