The term was used by the US Government to name a report being made by INS about illegal alien borders crossings from mexico---the name of the report was "Operation wetback". It defined the estimated amounts of illegals entering the country at the time and outlined a plan to "Combat" the problem. The report was written in the early 80's. After it was pointed out to the reports writers(several years later) that the term "wetback" was considered "rascist" and demeaning the writers issued an apology.
You know what? Its like all the other terms for putting down someone for their ethnic backgrounds. The term redneck, whitebread, whitey, gringo and several others are the same as ******, spic, wop, kike and so on, but you dont hear screaming about a caucasion being called a redneck.........
If You cant guess the word that was stared out above it was the N-word and points out that some slurs are more equal than others....So get a grip people, or star out the word redneck and wetback because it is as much a slur as the N-word