historically, conservatives supported mercantilism, while liberals supported free trade. this is actually the etymological origin of the terms conservative and liberal in our political system - it refers to the nature of the trade policies supported by each party.
in canada, the conservative party officially opposed free trade until roughly 1985, when it all of a sudden embraced the results of the mcdonald commission, designed to seek renewed reciprocity with the americans, something that nafta is definitely not.
so, if you look at the situation at face value, it seems as though the conservatives switched sides. but, they haven't, actually. rather, the language has reversed. it really is right out of orwell.
it's actually the liberals that switched sides, by embracing a nafta that uses the language of free trade but is, in truth a fundamentally mercantilist agreement. chretien ran against it, but found himself stuck when he got into office, unable to actually undo it. mulroney had sold us out....
despite launching the committee that led to it, the most vocally prominent opponent of nafta in canada until the day he died was in truth almost certainly pierre elliot trudeau.
so, when i attack doug ford as a mercantilist conservative, it's being done in the context of a british-canadian political tradition. that might be confusing to you if you live in the united states, but all i can tell you is that we're a different country and that you'll need to learn the history if you want to follow the discussion.