I thought they had NAFTA to reduce / eliminate tariffs between Canada, USA and Mexico, and I thought Trump then renegotiated NAFTA in his first term for the Maga win.
Sounds like either you're peddling 'alternative facts' yet again, or the master of deal making got his pants pulled down in the renegotiations if Canada can sell to the US tariff free while the US has to pay to sell in Canada.