As a first-order approximation, transoceanic shipping is essentially free. A quick google gives me $5,000 to ship a container from China to a US port. Considering the volume that a 40' container can hold, yeah, that's pretty much free.
Compare that to even cheap US labor rates and it's a no-brainer.
The stated goal only matters insofar as it affects the policies that are created.
In 2018, it's a whole lot easier to avoid doing any manufacturing in the US than it is to avoid using any components made in China; and both approaches avoid the tariff as written.
If the goal is to bring back component manufacturing, they need to go back to the drawing board.