"When Canadian jobs start moving to Mexico to replace Mexican jobs repatriated to the United States"

What alternate universe are you living in? Canada lost a million jobs in manufacturing TO THE US when "free trade" came in in the early 90s. There are few left to "move to Mexico". As a result of "free trade" it took the Canadian economy more than a decade to partially recover. 

As soon as they could, American companies moved these jobs - mainly to CHINA not Mexico. The main reason was not cheap labour, no safety and environment standards and no oversight of product safety and lack of poisonous ingredients  - although this was a factor. The main reason is that these multi nationals could then "earn" all their profits in tax havens. This is the real issue and you can bet your bottom dollar that Trump will do nothing about this - because he is benefiting as much as all the other wealthy Americans who own major corporations. This is all a ruse to help him and his wealthy friends.