If they've been "poisoned," it was far more likely at home.

Some public secondary schools may *mention* creationism as an "alternative theory," but science teachers are far more likely to avoid the whole topic of evolution as "too controversial." They don't want to end up debating the parents.

But because the United States is not a "theocracy," public school teachers cannot legitimately "teach" creationism (and I don't know what percentage even wants to, at least in a science class). What's more, dedicated creationist parents can home-school or, if they can afford it, send their kids to a private fundamentalist religious school.