I know I'm preaching to the choir here, but this article exposes the folly of protectionism well.
Some say imports are bad for the economy. But consider one implication of that belief. It would mean that during war you'd want to ship your enemy as many goods as possible. After all, the imports would hurt his economy, right?
Obviously the exact opposite is true. A nation at war wants to block its enemy's trade precisely because trade is beneficial.
Thus protectionists, in the words of one economist, "want to do to their own country during peacetime what the country's enemies would wish to do to it during wartime–that is, close its borders to imports."
Many think of free trade in terms of nations doing business. One hears that America has so many millions of dollars worth of trade with Taiwan, for example, and so many millions with Singapore. But actually the commerce is between companies, not countries.