That's a really silly argument. How MUCH higher would it be if 100,000 factories that went overseas were still here?
A lot of them didn’t go over seas, a lot of them were just replaced with capacity here.
The fact is manufacturing is no longer a people employing industry. Not here. Not anywhere. Automated factories produce more with lower footprints and lower overall cost. Manufacturing jobs are disappearing globally and will not be coming back. Even if you bring back the factories the jobs will not return.
Implicit in your statement is the assumption that companies that can’t sell their stuff would still be in business and in fact around to hire unneeded people
Perhaps instead of a tariff it may be better to have a law that makes it illegal to close factories. Well of course if none of those fabled 100,000 factories, nice round number that it is, had left employment may be a little higher. But they would have still drastically curtailed employment.
Again industrial output is at near record levels maybe it could be higher but jobs are going to continue to decline. Higher employment costs means less jobs and more robots and automation. Many US workers are priced out of the labor market thanks to the myriad government rules and regulations and industry protection rackets such as sugar tariffs.