You don't think the myriad contracts and negotiations that will then need to go on every time someone wants to import something will raise the price? What will happen is a bunch of products will simply no longer be available... via legit means, at least. Ah the black market. But at least no one gets hurt by a black market, right?
To be honest I don't know exactly what the impact would be. I can only guess. The bottom line is that American workers shouldn't have to compete against slave labor in places like China, India, Malaysia, etc.
My preferred solution is voluntary economic cooperatives.