If the murky clouds of Trumpian nihilism are dragging down your spirits, we have a quick little mood stabilizer for you: go to the website of the London Metals Exchange and gawp at the price chart for Platts’ index of the “Aluminum Premium Duty Paid US Midwest.” The hockey stick you’ll see there is a picture of President Donald Trump’s off-the-cuff tariff threats against Canada landing squarely on the skulls of middle American manufacturers and consumers. They are, as of Wednesday, paying US$400 (C$570) a tonne more for aluminum, most of it Canadian, than they did before Trump was elected. You would have to have a heart of stone, or perhaps cold gray rolled aluminum, not to laugh.