and if they go below <x> they pay a fine yea?
yea, thats what a tariff is. you have to manufacture x=100% domestically. otherwise 100-x non-domestic is taxed. that's a tariff.
Pay 300% tax if you don't manufacture 10% of your goods in the US. Furthermore, the penalties could escalate from repeat violations. It's a lot more flexible than a blanket tariff on an industry, country or specific good.
Where did I say that? No, the point would be if you don't manufacture x% here, you can't sell here. That is the only surefire way to force domestic production.
Tariffs don't encourage re-shoring and domestic production, they just raise the barrier of entry on consumers.