> But did we run that experiment while foreign alternatives were nearly or equally expensive?
Tariffs will have to go a lot higher than 145% for this to be a relevant question. US labor (and now due to tariffs, raw materials) costs are so much higher that frequently even doubling the import price would not make US cost-competitive.
> Are you suggesting former factory workers all became scientists and engineers?
No, I am suggesting that those people currently work in jobs that support higher productivity of the overall labor force, and that higher productivity creates the conditions necessary for increased prosperity for Americans.
Let's take QA for example as something that is often thought of as lower-skilled (but which is not) job that a hypothetical former factory worker could retrain to do. A person could QA a T-shirt or QA the Netflix app. The Netflix QA impacts more flow of money than a T-shirt QA, and so supports higher income for everyone working at Netflix than those working in a T-shirt factory. It is not possible for a person to manually QA enough shirts to have a similar economic impact as QAing the Netflix app.
Or compare the typical factory worker to a profession that is often denigrated in the US: retail. A factory worker making cutlery or light bulbs will generate less money for the economy than the average Costco employee[1].
Or look at a company that moves these goods around, like UPS. $360k revenue per employee @ 21% gross margin.
> Is the result of that a higher median income, or is it a reflection of a higher wealth inequality?
This is the continued choice of the US polity to not use our wealth to improve our common good. We instead choose to allocate it in ways that are markedly different from other rich and developing nations. So a high-productivity state with a higher GDP per capita than the UK is "poor" because our chosen combination of labor laws, tax laws, etc. are designed to produce that outcome. There used to be robust debate about the best way to make our economy less anxiety-inducing for individuals, but that discourse ended and everybody pretty much accepts that this is how it has to be. Nonetheless, we are allowed to choose differently.
1 - Costco produces close to $100k of gross profit per employee. This is multiples of the prevailing wage even in rich countries in Western Europe, much less countries like China.