This article is right on. I have an EXTREMELY leftist World History Teacher who daily rants about our President and calls anyone who votes for him to be outright stupid. She is VERY open in her political beliefs to the class and baisically does not tolerate any other opinions, although I have tried on various occaisions to point out where she is wrong. (which is everyone!) To make a perfect example, yesterday she said Hillary Clinton would make a WONDERFUL President. I almost puked.
Argh, I just thought of something else which just miffed me the other day. She said that generally she was against abortion, but no laws should be made against it because that would be gender biased and unfair for women. I wanted to scream.
You could ask your school board (the heck with the principal-say it in public so you have witnesses to safeguard your grades.) if your teacher is paid for her opinions.
You should find out about the David Horowitz's Students Bill of Rights and have it with you.