Canada has tariffs against US food imports because the US just subsidizes it so much. So what if we allowed a shop that sells only to social-assistance recipients to import US food tariff-free? I presume that the state could provide a government card to social-assistance recipients and a registered shop would be allowed to sell its US-subsidized food to them tariff-free. Think about it! US taxpayers would be subsidizing our poor's food purchases. Brilliant, no?