What companies are going to "comeback home", Dezzy?
Let's say it takes $10 billion to build a car factory in Detroit. Is Ford going to actually do that when Trump is so erratic that he might revoke the tariffs next month or next year.
Companies returning to the US is a decade-long endeavour. No car company is going to engage in that in a highly unstable economic environment. If Ford builds a car plant in Detroit and Trump yanks the tariffs, then the new Detroit car plant is immediately totally useless because production moves back to low-wage Mexico again. There's a reason the car companies moved to Mexico to begin with.