important, it's not how we keep ourselves fed (see linked listing)...conversely, other countries have ratios much higher, and therefore will need to find better trading partners, as Fareed Zakaria mentions.
If Trump were to follow through on this strategy, it would take an awful lot of Capital to build out the infrastructure here in the U.S. for all that added manufacturing...AND...it would most likely take decades to finalize...and pay back. If other countries don't send us Dollars, then that will make it harder for us to fund such construction.
Add to this the shortage of workers over that period due to a low birth rate, retiring Boomers and anti-immigration policies, it's not clear that we could actually operate those facilities...assuming enough nations wanted to do business with us. BTW, Florida recently started looking into amending Child Labor Laws because of worker shortages.
Either Trump isn't all that smart, or he's simply following Putin's instructions...Either way, this scheme needs to be stopped.
Link: https://en.wikipedia.org/wiki/List_of_countries_by_trade-to-GDP_ratio