The problem is that when teachers bring up politics in class, it never IS an open discussion. Some of the things that are said are not only offensive but completely and utterly inappropriate. Because of the economic element of this election, I have had teachers who have gotten into money discussions. Is it okay to ask students how much money their parents make?
I don't think so.
It is illegal but there isn't much the administration can or will do about it, unless kids start recording classes.