Why does the United States want to move all manufacturing to domestic production?

Your question isn't worded correctly, it should read.

Question:

Why does President Trump say he wants to move all manufacturing to domestic production, and why do many of his supporters support this idea?

Short Answer:

For many of President Trump's supporters it's just ignorance of how the economy works. Faith in their guy, President Trump, that he won't take advantage of them and that he knows what he's doing. For President Trump and his advisors, it appears to be sowing anger with others to justify what they are doing which is monetizing the Presidency and the US economy for their personal benefit.

Answer:

President Trump is selling a narrative that because the United States has run a massive trade deficit to the tune of hundreds of billions of dollars with China and smaller systemic deficits with others like Germany that this is evidence that somehow trade is unfair. That if these countries weren't "cheating" the U.S. economy would be stronger, with more jobs, better pay and basically their standards of living would improve. This is just untrue and President Trump and his advisors know it. Both President Trump and Vice President Vance were asked during their debates to address the fact that 20 Nobel prize winning economists said his policies of sanctions and "onshoring" would shrink the US economy their answers were, "they could be wrong". They can't name a single respected economist which supports their plans. Certainly not Keynesian economists who have been prominent since the great depression, but also not the Chicago School of economics or Milton Friedman which has been prominent since the 1980's and traditionally favored by Republicans.

Here is how it works, every American runs a trade deficit with their grocery store, dept store, and Amazon.com. If the government put a tax on those retail outlets that doesn't help the consumer, it makes the costs go up and the consumer either does without or buys less. Their personal deficit is not bad for the consumer because they get goods from those sources which they need at a reasonable price. It all works out because the consumer has other avenues like employers where they receive more funds than they spend in exchange for their time and expertise.

The reason why onshoring is bad is because there is a reason the jobs left, generally because the offshore country could do the job more efficiently and yield a cheaper product. So to bring that production back to the U.S. again means paying more and doing with less. About the trillions of trade deficits which some are so bent over, that’s not an optimal thing but it’s really not a bad thing either. Every deficit dollar must return to the U.S. to achieve full value. So even if china puts those dollars in their mattress for years most will still eventually come home to buy American goods which is a good thing.

Bottom line as the worlds largest most diverse economy prior to Trump we have done well under free trade as many other countries have. To turn away from what has made us suucessful to a protectionist market is beyond stupid. That is literally the economic model followed by China and India when they were among the poorest in the world, china in the 70s India in the 80s.

Nobody honestly wants to move all of the United States' manufacturing to domestic production, because doing so is simply not possible in a predominantly service-based capitalist economy like that nation's.

The reason that Western capitalist economies, including the USA's, have boomed since the end of World War II is due to the ability to offshore manufacturing to foreign nations where it is cheaper to produce goods. This is because those nations' standards of living are lower than that of Western economies, therefore their cost of labour - the #1 expense for employers - is correspondingly lower.

Tariffs nominally redress this balance by adding an arbitrary tax on foreign imports, making it more expensive to import goods produced overseas. In practice tariffs have fallen out of favour because they are trivially circumvented:

• Country A places tariffs on country B, such that importing from B to A is no longer economically viable
• Solution: B instead exports its goods to country C, which A has not imposed tariffs on, and thence from C to A

There are various ways that attempt to prevent such circumvention from happening, such as requiring a certain percentage of every import to be constructed in the importing country, but these themselves can be worked around. Ultimately, tariff enforcement becomes a game of whack-a-mole in which huge numbers of people are employed to expend huge amounts of time and government money to make sure that imports aren't evading tariffs. It's a losing proposition.

But say that tariffs work. Say that every company that currently offshores their manual labour decides to bring it back to the USA. The problem is that there aren't enough people on the USA willing to do that labour, because the USA - like every other Western economy - has long since transitioned from being a goods-based economy to a service-based one. The primary reason for this is that the latter type of job is perceived to generate more economic value, therefore is paid better, and thus citizens prefer such jobs. The end result is that even if manufacturing jobs were brought back to the USA, nobody would want to do them, because they don't pay well enough.

That's the one-punch, but the two-knockout blow is automation. Because human labour is the most expensive (and unreliable) part of any business, replacing humans with machines that do the same work for far less money and without needing to eat or sleep, has been a focus of capitalist manufacturing since the dawn of time. Even in the economies where manual labour is cheapest, automation has made inroads into manufacturing because it's cheaper, with the result that manual labour is starting to become economically unviable there. And it will only get worse.

In short, what really needs to happen for manufacturing jobs to come back to the USA is the following:

• tariffs on foreign imports to make them economically unviable compared to producing locally
• manual labour jobs to pay as well as or better than service ones
• automation of manual labour to be restricted or banned, such that manual labour jobs remain plentiful and thus wages high

The first one is simple and has already been done. The other two... well, they're far more difficult. How do you force companies to pay a higher wage for a manual-labour job? You could subsidise them, but that'll never happen because that's communism according to Trump and co. As for preventing automation... yeah good luck with that.

So essentially there is no conceivable world in which manufacturing jobs can and will come back to the USA en masse, because the fundamental economics of capitalism simply don't allow it. Anyone with a basic grasp of those economics can see this; Trump and his voters cannot. But then their grasp on the basics of anything, except ignorance and bigotry, has always been tenuous.

In short, this is not a sane or coherent policy, merely a populist tactic to appeal to a voting base that has neither understanding nor care for economic realities. It's not a question of whether this "policy" will fail; it could never succeed. And ultimately the only ones who will benefit are Trump and his cronies who are using this "policy" to manipulate the market to enrich themselves at the expense of everyone else.

It's a political priority to Trump (not the United States) that manufacturing jobs be returned as his voters are those who lost out from the offshoring of these jobs.

The more jobs the US admin tries to repatriate, the more they'll regain. Hence the Tarzan hollers from the White House. If he delivers on repatriating even 10% of the jobs moved overseas to low-cost labor states, he - and his allies - are home and dry politically.

If he fails on it, he's a dead duck in politics.