Missed Opportunity President Trump shut down trade negotiations and said he would add 10 percent more tariffs on Canadian goods in retaliation for a pro-free trade advertisement in Ontario. Ontario Premier Doug Ford is bragging that the ad was effective and chortles over the ad getting under Trump’s skin. Mr. Trump called the ad an attempt to interfere with a U.S. Supreme Court decision on the legality of the President’s tariffs but this is a missed opportunity. The better retort is to call for Ford and Prime Minister Carney to remove the protectionist supply management program that restricts imports of dairy and poultry. Ford is getting to falsely present himself and Canada as a bastion of free trade. He argues that U.S. tariff...