I would just like to say that it is rediculous to use the word "liberal" as you would the word "*******" or "dumb ****". To say that someone is liberal, in the way that most americans do, is like saying they are terrible human beings or un-patriotic.
However, it makes me sad that the only way to get around this situation without harming your children is to just let it slide and bite the bullet. Sounds like this teacher has the same problem as a small percentage of police officers do...he needs to be in a different profession. He has a hard on for politics and propaganda, not for teaching children. He needs to get out of teaching altogether so he does not damage anymore young minds.