The only time when I would condone protectionism would be the "infant industry" cases of emerging technologies and products that have promise as a US industry. However, having the highest amount of Research and Development in the world, the U.S. tends to be on the cutting edge of new products and technologies.
As has been said, quotas and tariffs do not improve the domestic market's quality or choice when strictly used as a tool to promote industry. Eventually, things can be done cheaper elsewhere, and they will be. For example, besides a few cases such as American Appearal, can you name any American clothing manufacturers?
Another case is the voluntary export restraints on Japanese autos. The cars came in cheaper and GM and Ford could not compete. When the Japanese cut exports, quality sank in most U.S. lines of autos and were able to raise their prices and so were the Japanese (they produced less and charged more), meaning more profits. Now, those profits are entering the U.S. in new production plants throughout the U.S. where the import restrictions don't exist since they are being produced here.
As has been said, quotas and tariffs do not improve the domestic market's quality or choice when strictly used as a tool to promote industry. Eventually, things can be done cheaper elsewhere, and they will be. For example, besides a few cases such as American Appearal, can you name any American clothing manufacturers?
Another case is the voluntary export restraints on Japanese autos. The cars came in cheaper and GM and Ford could not compete. When the Japanese cut exports, quality sank in most U.S. lines of autos and were able to raise their prices and so were the Japanese (they produced less and charged more), meaning more profits. Now, those profits are entering the U.S. in new production plants throughout the U.S. where the import restrictions don't exist since they are being produced here.