Additionally, there is a strong ethical argument against protectionism. "Buy American" is essentially a racist statement. You're implying that the value of an American is higher than that of someone from another country by saying that it's better to protect industries in this country to protect the jobs. At some point, we've got to start calling out "Buy American" for the racist statement that it is.
Not completely on topic, but something I'd like to add to this. When I purchase things, usually of the food variety, I check to see where it originates from. I try to avoid purchasing things like, apples from china, oranges from brazil, etc... mainly because of the transportation costs associated with such an operation. I am in inadvertently 'Buy(ing) American', but really aiming to buy local products. I am by no means saying that people should or do purchase cars based on locality, just that some types of products lend themselves more to this type of purchase.
COMPASS [for the CDC-6000 series] is the sort of assembler one expects from a corporation whose president codes in octal. -- J.N. Gray