This topic is also a hot topic on many other forums which I attend.
Another poster in another forum had an interesting thought: that this import duty is a mischievous way to offset the revenue shortfall caused by the tax reform. By hiding this duty (tax) on the final product's price, they can avoid calling it a "tax", which would be political suicide.
ACA became a law. It was completely internal to US, meaning it is a tax even though it is not called tax, and President Obama served two terms so it was not political suicide for him.
On the other hand, the Congress did turn over quiet a bit because of ACA passing, so it was political suicide for many congress persons.
Basically any government action that increases government income can be interpreted as some kind of tax.
If you want another interesting idea in addition to the one you already listed, here is one: there is an item that has increased tariff, the vendor brings it from China, pays the tariff and then increases sales price of the item to compensate for increased cost. The vendor resides in a state that has a Sales Tax (7% in my state). When a customer comes to buy this item, the customer pays sales tax. So. The item used to cost 100 USD, my sales tax is 7% so I paid 107 USD with 7 USD going to the state government. Now the cost of the item is increased by 25%, it is now 125 USD, with 7% sales tax price becomes 133.75 USD with 8.75 USD going to the state government.