A protected industry benefits from less import competition. It uses that protection to raise prices for consumers and to earn higher profits. It should be emphasized that these higher price and profits are not an unexpected outcome--they are the mechanism through which import tariffs help domestic firms. To put it another way, if tariffs didn't help domestic companies charge more and raise their profits, there would be no point to having such tariffs in the first place.
Hufbauer and Jung write:
"Calculations show that Trump’s tariffs raise the price of steel products by nearly 9 percent. Higher steel prices will raise the pre-tax earnings of steel firms by $2.4 billion in 2018. But they will also push up costs for steel users by $5.6 billion. Yes, these actions create 8,700 jobs in the US steel industry. Yet for each new job, steel firms will earn $270,000 of additional pre-tax profits. And steel users will pay an extra $650,000 for each job created."Many studies over the years find that trade protectionism saves jobs, but at a high cost to consumers (For example, here's an example of how the Obama administration tariffs on imported tires cost consumers about $900,000 per job saved in that industry.) The underlying issue is that consumers aren't just paying higher prices to save US jobs--if that was the tradeoff, we could argue over whether it might be worth doing. But the higher prices are part of higher revenue for steel companies, which maybe used for purposes ranging from robots and automation to research and development, or higher profits for shareholders and higher bonuses for managers.
In addition, any jobs saved for US steelworkers are not a net gain for the US economy. The higher costs of steel are then passed along to products, leading to lower sales for those industries. The Whirlpool company offers a vivid example. The company strongly supported the Trump administration when it put tariffs on imported washing machines, which helped Whirlpool. But then when the Trump administration put tariffs on steel, driving up the price of making a washing machine in the US, it hurt Whirlpool. As the head of Whirlpool said: "the net impact of all remedies and tariffs has turned into a headwind for us."
Hufbauer and Jung mention (without endorsing) some estimates that the steel tariffs could be a net loss in US jobs by the time that the effects of higher steel prices are passed through industrial supply chains, making many products more expensive to make within US borders. And of course, these calculations don't take into account the economic effects of retaliation from other countries, and how that costs US jobs in other industries.
Again, this dismal cost/benefit calculation for the steel tariffs is utterly unsurprising. Steel tariffs are just an indirect subsidy to the steel industry. Sure, US steel tariffs also make foreign steel producers unhappy, but the happiness or unhappiness of foreign producers is not a useful goal for US economic policy. The main costs of the steel tariffs are imposed on US firms that use steel (and will have a harder time selling inside and outside the US) and ultimately on US consumers (who will pay more than consumers around the world for products containing steel).