The alliterative is fairness. If we're going to have an EPA and OSHA and the rest, then we have to tax imports from places that don't in proportion to the degree that they don't. Otherwise we have to drop these protections and be content with huffing pollution. After all, if we want to enjoy super-cheap manufactured goods then it's only fair that we also "enjoy" the externalities of this production. Either way it's fair to our working class. They get jobs.
I'm 100% in favor of free trade with other first world countries, where first world is defined as having these protections in place and having a living wage. This would be fair and would not lead to mass unemployment and economic destruction. Free trade with Canada, Europe, Australia, or Japan is not going to de-industrialize the entire USA. It might result in periodic disruption of certain industries (e.g. Japan with autos) but it would not result in the kind of total lasting decimation we are seeing.
Edit:
Cue someone coming in and citing some GDP stats and telling me everything is okay. Sorry, but you're wrong. The stats you are citing are not capturing the reality because they are including everything and everyone and everywhere. They are averages. Do a GDP stat and exclude San Francisco, New York, Los Angeles, DC, Seattle, Portland, and college towns, and then we'll talk.