[DoodleDawg]

Because of the shortfall of US production. Supply vs demand issues.

And how is a tariff going to help that?

[DarthVader]

Tariff makes foreign steel more expensive and provides incentives for US manufacturers to increase production by reopening old plants ans builds new ones because their products can be cheaper and favored.

Here is a story which will explain:

https://www.wsj.com/articles/u-s-steel-to-restart-illinois-plant-operations-to-handle-demand-1520430223