There's a lot the president can do with executive orders, and of course the departments of the government that enforce rules and such are led by people who serve at the pleasure of the president, so there's that. In the long run, yeah, there are too many forces working actively against this sort of protectionism to make it stick in all probability.
It's so dumb, too. At least in the old days--when the unions would have rallies where you'd pay five bucks to swing a sledge hammer at a Japanese car--the stupid protectionist rhetoric was at least directed against manufacturers who were actually selling cars in sufficient numbers to average Americans that you could build a plausible (barely) argument for trade barriers. Not a good argument, mind you, but at least one that wasn't batshit crazy (and at at least one of those rallies they were bashing on a Subaru, a car that at that point was not exactly selling like hotcakes).
As many others have noted, the market does actually work. People buy cars they want; the Japanese, Koreans, and Germans aren't forcing people at gun point to buy their vehicles. And often, the cars are more, not less, expensive than American cars.
Notably, you don't see Detroit supporting stupidity like this. All the American automakers (if we can use a national label like that in this day and age) are global companies (FCA is just the most obvious and visible example), and any sort of nationalist protectionism makes their shareholders and boards very uneasy.
