Danielle Barden and I write on tariffs . A slice:
Raising the prices that American consumers and businesses pay for imported goods through taxes effectively decreases our incomes and increases production costs for the goods we produce.
This hurts  the poorest Americans the most, who spend more of their total income on consumable products.
Furthermore, if Trump’s aim is to create jobs in the United States, tariffs are actually counterproductive. Again, many businesses rely on imported goods — including, of course, from China — to create their products.
Businesses don’t like uncertainty over the future course of the economy or policy. It makes them less likely to expand their operations, hire more workers, and do the things that generally make American living standards rise. By making the Nafta agreement temporary, international economic policy among the three members becomes far harder to predict.