It's hard to say anything with certainty. Obama's tariffs were 55% on Chinese tires, a much higher tariff on a much more specific product from a specific country. Bush's steel tariffs were of minimal success according to the ITC and also exempted Canada and a lot of other countries. That the EU has decided to target Harley Davidson - ergo Wisconsin - ergo Paul Ryan and Bourbon - ergo Kentucky - ergo Mitch McConnell does a pretty good job of demonstrating that most people think a little harder about this shit than Trump does. I'm sure as hell not in support of trade wars and there are certainly better ways of dealing with China's loss-leader approach to metals refining but the market is most assuredly reacting to uncertainty rather than policy... as they should.
The stupid-like-a-fox Trump oracles have suggested that the real reason he's in favor of steel tariffs is that the industry that's most sensitive to the price of steel is commercial building, thus driving up the price of existing units (due to a projected slow down in building). Seems specious, but needs to be explored, because if Trump can benefit even to the tune of a dollar at everyone else's expense, you know he'll do it.
^^^^^^^^^^^^^FTFY I refuse to crawl into that man's skull. Enough people have tried and come back broken. I'll argue that he's a creature of the Id and will gladly grab for shiny baubles, no matter how illusory they may be.if Trump THINKS HE can benefit even to the tune of a dollar at everyone else's expense, you know he'll do it.