Our markets are open to the world because we are smart enough to know that when you erect trade barriers you're shooting yourself in the foot.
Take steel for example, when Bush put up tariffs on foreign steel he protected the domestic steel industry sure, but he also screwed over every other company in the US that uses steel to make its products.
He also screwed over all the consumers who buy anything that is made with steel.
yea, that is the downside of protecting your market, you pay more until your domestic production is a good as foriegn production. Some time due to circumstance beyond your control you can never match the imports. Oh Well. Ain't no prefect man made system yet.