Realistically if they are doing 20% of their US business in say Vermont, they should have to employ 20% of their workforce there. 15% in California? 15% of US head count in California. All they do is extract and hide the money. That needs to stop. Don't want to? Well your competition and new entrants will.
So if you're doing B2B business primarily within the US, you have to hire/fire a bunch of employees in different states every time you sign a new contract? That sounds incredibly burdensome.
There are singular companies doing extremely specialized work for entities all over the country, so this kind of logic is not going to work. It would be more realistic (but similarly problematic) to apply the logic on a national level. But what that would look like is the government issuing licenses to import based on the percentage of the company's output made domestically. That is complex to figure out, as well, and not all products are made entirely in one country. Even if they can be made all in one country, it may not be what you want your countrymen working on. I would rather see my people make cars than, say, squeaky dog toys. But some of the same skills can be used for a variety of different products too.
By this logic, if a single person in Romania purchases a product from me, I must hire someone in Romania or else the transaction is unethical? Immoral?
If I only need 10 developers to make some software and sell it globally why should I have to hire more people?