The Globe and Mail reports in its Saturday edition that as obnoxious as he is, Donald Trump may actually be doing Canada some good. The Globe's Marcus Gee writes that his demands are forcing this country to rethink bad ideas and question sacred cows. Just last week, the U.S. President gave Prime Minister Mark Carney an excuse to jettison a wrong-headed tax on foreign tech giants. The money that was to flow to Ottawa from the tax would have come from the pockets of the millions of Canadians who use Facebook, Amazon, Apple, Google and other tech giants. Mr. Carney duly killed it. A capitulation? No, a sensible concession. Mr. Trump's Blame Canada campaign is forcing us to reconsider the way we do things. Start with national defence. Canada and other NATO countries have been freeloading off the U.S., relying on Washington to keep the Western alliance well armed while scrimping on armaments themselves. Even Canada's system of supply management is getting a second look. Under this Soviet-style scheme, marketing boards, rather than the free market, govern the output of eggs, milk, cheese and poultry. The agriculture lobby is so strong that no government has dared to dismantle it. Whether Mr. Carney's will remains to be seen.