"War is God's way of teaching Americans geography." -Ambrose Bierce
I would let the school know that in the future you want to be notified ahead of time of any videos, slides, etc....that will be used in class.
I taught public school for years (but never again . . . no, never again). The teacher is probably "sandbagging." This is pretty common in April. My guess is that you have a case of burnout or incompetence here.
People have perspectives. People who are open about their perspective - "I am an American conservative," or "I am an American socialist" - position themselves as being philosophical (the term "philosophy," after all, simply means "love of wisdom" - which is entirely different from claiming to be wise).But, they have a responsibility to differentiate between teaching their assigned subject, and politically indoctrinating their students. There can be no commingling of the two in a public school.People who claim to be "moderate," or "objective," OTOH, position themselves as being sophists (since "moderation" and "objectivity" are virtues, to claim either of them is to claim superior wisdom and thus to arrogantly talk down to people who in principle may know something that you should listen to).
When a geography teacher teaches about places and the cultures to be found in them, that teacher speaks with authority and presumptively can cite noncontroversial references for whatever he says. When a teacher teaches the perspective of one political party only, that is obviously an abuse. Yet, even "balancing" Fahrenheit 911 with Fahrenhype 911 simply compounds the felony - because the actual felony is not telling only one side, but inculcuating the idea that the students should accept political discourse in binary, Read-Only, form.That isn't the only way to do politics - and it's certainly not the way we do it here at FR.
Why not identify the school and the teacher? Why would you want to protect their identities? We can only deal with these offenders if they are drug out into the light of day.