text: So let's make absolutely sure we understand this story. The US Education secretary's cancellation of her visit to Ontario schools is welcomed by the teachers' unions.  Why?  Isn't the entire point of teaching and learning to expose students to as wide a selection as possible of ideas from all over the world so that they can better understand matters at home? Granted Ms DeVos's views may be radically different from the unions'  but so what?  Are our own ideas about education so precarious they would collapse if confronted by a proponent of an alternative theory? The logical extension of this union paranoia about cross-pollination of teaching ideas would be that Ontario teachers should be banned from visiting other countries and their schools. Seems to me we elect school board trustees to run the schools and entrust them to invite suitable people to visit with and possibly talk to our students.  Last time I voted, the union wasn't on the ballot.