Are they huge, multi-block facilities? No! That's the thing with automation - the cost to make something has dropped so much, and the workforce needed has dropped dramatically, that a small 5000 square foot facility can do what used to need 10 times that amount of space. You don't need a labor force of 200 trained machinists; you need a dozen machine maintenance workers and a half- dozen engineers. Replace 200 blue collar workers with 12, and add half a dozen white collar guys. Done.
A single Haas CNC multi-turret machine (built 10 miles from me, right in Oxnard, California) can do the work of 50 machines of the 1970s. And all with a couple of people, rather than 90+. And in 100 square feet, versus the 3000 needed for those 50 lathes and mills of old.
The automated factories are increasingly smaller and distributed. With 3D printing (led by Stratasys, a Minnesota company that builds in Minnesota) changing the way things are done, including the use of such parts in production volume as the quality of the process continues to grow, that will further dilute and distribute manufacturing.
3D metal sintering. In another 3-4 years it will be cheaper for your company to buy a couple of such machines and just make parts yourself, rather than employing a centralized 3rd party manufacturer with a huge facility somewhere. Those thousands of jobs in a massive facility are being dispersed to hundreds of locations with a couple of workers at each location. Cutting employment dramatically, as well as actual plant size.
A 20% tariff would repatriate manufacturing, balance the budget and reduce the trade deficit. Win-Win.