It doesn't look as if free trade is really hurting us. One needs more than a bit of courage to write that this country is fortunate enough to attract immigrants. I can tell you that lot of people do not have such an opinion. A. Unfortunately, some Americans fear new immigrants will somehow pollute our culture. They simply don't believe in the power of their own heritage.
American culture dominates the world.
Sure, this country will change with each new immigrant wave. I do wonder what the consequences of some poorly researched or tested actions rushed into use could have on our lives in the next generation. We read every day how common everyday pests are becoming more and more resistant to long-proven treatments. You mention three examples where taking the safe approach created more harm than good. A valid point, but only if you aren't the one who experiences the problem up close and personal, say in losing a loved one or your own life because of the unsafe practice.