Former President and Republican Presidential candidate Donald Trump says he wants to “once again turn America into the manufacturing superpower of the world,” and that a couple of the ways he’d achieve that would be to reduce the corporate tax rate to 15% for those companies that make their products in the US and by applying tariffs on foreign-made goods.

One question concerns how strictly he’d apply that tax break criterion—or how strictly Congress would allow him to. Would making their products in the US include or exclude companies who assemble their products in the US, but do so from components or subassemblies that are imported? If implemented in some form, would the exclusion include components or subassemblies that are made in USMCA members Mexico and Canada?

The subassembly bit especially would impact the several car companies that assemble their vehicles in the US, but these are far from the only companies that do that. Which brings up another question: what about those international companies headquartered in other nations but that assemble/manufacture in US factories products for sale in the US. Would the 15% tax apply to the US component of those businesses? To the whole foreign-domiciled company?

How would the tariffs apply to the components imported for final product assembly? How would the tariffs apply to those foreign-headquartered companies that bring in components for final assembly in the US and sale in the US?

Answers need not block either of the two proposals, but they do need to be worked out.