> As another example, if Tesla sells Model 3s for $50,000 and BYD comes in with a similar spec car priced at $25,000, then putting a 100% tariff on it will drive BYD's effective price up to $50,000 allowing Tesla to compete without undercutting or outright selling at a loss.

Doesn't that mean that American will have to pay $50 000 for a car that is worth $25 000? While people in other countries will be able to buy cars cheaper, buy more of them and maybe it somehow improves their life quality.

The purpose is to prop up local companies.

Which is not always a bad idea, having a local supply and innovation of something can be rather important, local money is less "Gone" than foreign money, think of how healthy small towns are when all of the shops are local vs when they are not.

The problem comes when there is no realistic local competition. If you don't make something locally at all, an import tariff is just a stupid tax.

Yes. Tariffs are bad for consumers. The supposed benefit is to manufacturers, since in that scenario Tesla will be able to sell its cars at a higher price and profit.

It means exactly that. It also means the American company will feel less pressure to improve cost or quality.