Very strange. I think it’s safe to assume that most of the students had never heard of the term “wetback,” which, for one thing, was rarely used in the Northeast where most of them probably come from, and secondly, is somewhat dated and hasn’t really been in general use for a long time. So I think explaining the term to them is certainly reasonable.
But what’s reason got to do with it?
In a PC world where reason is abandoned to be replaced by pluralism so that the historic reality that "wetbacks" are from Mexico and is a pejorative term is now a crime