I can understand a person's right to freedom of speech, and certainly that right must be protected in order to maintain our so-called democratic society. However, this jerk is a teacher whose hate-filled rants on his FB page, apparently a foundation of his beliefs, will certainly roll over into his classroom and have an effect on the students he comes into contact with.
While he is protected under this right, his teaching credentials should have been revoked or restricted so that he could not be in a position of authority and the school board should adopt new policies regarding what teachers and administrators can and can't say on their public web sites. There seems to be a double stand here when teachers can get away with putting this garbage in public view, yet when a student goes to apply for a job or college their web pages are considered into that process and they may be refused that job or acceptance into college based upon their comments on personal web sites. I would say that's a double standard.