I'm not overly concerned about it. It's my job as a parent to modulate the information they receive with school, and I'm fine with that. The most challenging part about it is they are asked to do assignments whose responses contain a strong political element, meaning there is a "right" opinion the teacher wants to hear. Again, that doesn't overly bother me. That's life, and my kids need to learn to operate in politically charged environments.
Yes, my children know what I think, and we discuss everything openly.