Not to mention the continued erosion of US court protection for American businesses. Mexican and Canadian "ministers" can out vote us, and even if it is against our National inerest will we be bound by their decision.
These agreements take decisions out of the hands of all of our legislatures an therefore our voters, and into the hands of "appointed ministers". Even if Mexico was as developed as the US and Canada, we would all still lose the ability of each of our voters to dictate our interests. Why must we give up normal nation state relations?