Trump is using century-old misinformation about tariffs to raise tax revenue to pay for tax cuts on the wealthy. In reality, it's an added tax on all spending that accelerates inflation.

Tariffs are theoretically supposed to encourage domestic production, but rely on the false premise that all raw and intermediate materials can be sourced domestically at a cost below the import price. That has generally proven to not work unless tariffs are in the hundreds of percent. But at that level, import taxes tend to poison entire sectors due to supply lag instead of drive domestic economies.