Why would you say only one or two? Even a class as far from political considerations as calculus would not be a welcoming place for a kid daring enough to wear a MAGA cap. And the vast majority of parents are products of the same left-wing indoctrination that begins in elementary school. Parents with strong enough character & control over their kids to counterbalance the public school indoctrination probably have their kids in a private school, if they can possibly afford it.