Trump's mercantilist tariffs are not good for the economy, but do remember it will not 'destroy' it. It's going to slightly increase the price of steel, and most things are not made entirely of steel.
Tariffs don't solve the main reason why factories left in the first place ... and no, "cheap labor" doesn't mean factories will leave - the price of labor in the long run converges to marginal productivity - firms should be indifferent to labor prices as long as that holds