It doesn’t matter how many times he’s told. Tariffs don’t work. The costs are not paid by the exporter. They are paid by the consumer. Tariffs don’t shift manufacturing of the goods imported onshore, they are supplied by other countries or substituted for lesser goods.
The consumer pays higher prices for end-user goods. The domestic members of the supply chain pay higher input prices while sclerotic domestic producers are subsidized to stay non-competitive.