Canadian exports make up for only 2 - 4% of the American economy - a negligible amount that the Americans can supplant from elsewhere. The US congress will not likely make a move.
Canada has some of the highest trade barriers and tariffs in the world and has an extremely protectionist trade policy. The NAFTA agreement has traditionally exclusively benefited Canada at the cost of America.
If you've ever traveled abroad, or tried to ship items from the states, you'll note that anything above the value of 20 $ CAD will be taxed upon import into Canada, while this limit is 750 $ USD if you import into the states. We have high dairy, lumber, mineral, and petroleum taxes in addition to massive VAT across all goods. Everything coming into Canada is slapped with a tariff and the consumers pay for it. We are one of the worst violators of the free-trade agreement, and were only included in the old 1994 treaty as a courtesy for borrowed airspace for the American NORAD program. As a result, Canada has some of the most anti-competition policies in the world and our goods and services industry is dominated by inefficient manufacturers and government sponsored contracts.
Lots of rhetoric but as that lady used to say in the Wendy's commercial "where's the meat?" You haven't really made more than accusations without any links for back up for your claims.
You mention a lot of taxes that we as Canadians pay but the subject is Free Trade; the Americans do not have to pay one cent in Duties on export if the product is majority of US Made Parts. We on the other hand pay in BC GST and PST as consumers of anything we import. If a Canadian manufacturer buys parts from the US, they are again Duty Free and they pay GST/PST. That company also files GST tax returns and from some sort of amazing math, they get a tax return on GST. The PST is claimed on the Provincial Side of their company tax return. I know because I am incorporated and file these returns via my accountant.
So let's focus on Dairy since its hot topic with the Mango eL Presidente.
Canada has a marketing system where farmers are paid to produce X amount of dairy, eggs, chickens etc per year and it's purchase is guaranteed by Canada and the Provinces.
https://en.wikipedia.org/wiki/Supply_management_(Canada)
The US on the other hand annually gives the dairy farmers in the US $22B of their tax payers money (last numbers I recall being 2015) to support dairy producers in the US. They do not have a maximum amount that they are allowed to produce. Given the farmers are needing a financial handout annually, they are running balls out producing dairy and many are still on the brink of bankruptcy. This format is also used by the European Union. All of these countries have their own protectionist rules against foreign dairy products entering their countries. Case in point Canada's deal with the EU fell apart because the Cheese makers in Italy would never support any foreign cheese in Italy.
https://www.newswire.ca/news-releases/american-dairy-farmers-depend-on-government-subsidies-673374473.html
Hence #45 trying to force the over production hormone laced piss tasting nasty US milk on the Canadians at what will most likely under cut our own farmers. We don't need their milk products and all it would do is undercut Canadian farms. Why would we ever support destroying our own dairy to get a deal with a megalomaniac who has openly showed his disdain for us?
And Guess What - our lumber is expensive because the US has always slapped duties on our lumber because the Billy Bob lumber companies in the South East USA are still using hand labour and have not modernized their own industry. Canada has for 3 decades had the most modern computerized systems employing lasers for exact cuts and do not have a labour intensive force because of our state of the art systems. The US has a different system where they sell the land to the large forestry companies at a huge discount and the company's grow their own timber and harvest it. Canada has crown land which they lease to forestry companies. Potato Pawtayto. Same thing but the US makes a big deal about it.
The claim our manufacturers are inefficient needs clarification. Which industries, where? I sell to OEM's across Canada and they would be holding back laughter if they read it. Everything is automated, barcoded, videoed, time stamped, robotics; you name it. These companies are well thought out and super efficient. Why, because our labour is expensive and to be competitive we need to have smart companies.
I am also interested in your claim that Canada is one of the worlds worst offenders of the Free Trade Agreement.
Canada has taken the US to the World Trade court and won every time. When it came to paying back the duties, they declined to pay up. Some fair freetrade agreement.
Canada giving Air Space to the USA as part of the 1994 Free Trade agreement? The US has had airspace to the Arctic since 1958. Where did you get that information? I'd love to read it.